D&D 5e: Homebrew Feats: Legendary Player Characters

So, I was tinkering around with the game one day and I got to thinking; why are only some things able to be legendary? Why is there no clear-cut distinction of what causes this aberrant members of extant groups? Why aren't there any legendary humanoids? Why can the player characters not transcend to this status of demi-epic?

I decided to, for the sake of extreme simulationism, create a framework in which a player character could become a legendary being in a very literal sense. I decided the easiest way to gate the ascension to legendary, is to break up the mechanical powers of the legendary group and then turn each of those chunks into feats. To get the full suite, you needed to take all of the feats, thus justifying how only high level/CR creatures can have the full set of powers and thus qualify as "legendary".

Breaking it into feats also makes it more modular, giving me more options when customizing monsters. If I wanted to create lower-power legendary monsters, I can pick and choose which parts of being legendary they actually have access to. For example, the boss of a goblin tribe might get a lair action- but that's it.

Here are the feats:

Legendary Resistance:

If you fail a saving throw, you can choose to succeed instead. You can do this up to 3 times. Uses of this feat are restored on a long rest.

Legendary Action:

You gain 3 legendary actions. You can use a legendary action at the end of another creature's turn. A legendary action can be spent to either move up to your speed, take an action, or activate a feat, feature, or trait. If an activated feat, feature, or trait requires an action or bonus action, it instead consumes the legendary action. You regain your legendary actions at the start of your turn.

Lair:

You gain 1 lair action. On initiative count 20, if you are within your lair, you may use your lair action to activate 1 lair feature. You may spend 30 days of downtime living in a location to convert it into your lair, giving that lair 1 lair feature. Lair features come in 2 types: Powers and Efects, and you choose which type to give your lair. Your lair can have up to 4 of each of the two types. You can give your lair additional features for spending additional downtime days living there, 180 downtime days for the second feature, 365 downtime days for a third feature, and 730 downtime days for a fourth. (For example, a fully built lair would have 4 powers and 4 effects, taking 7 years and 2 months to accomplish.) Choose features from the lair features lists.

(The entries in the lair features lists are directly extracted from monster entries. They have not been edited because damn that's a lot of work for no benefit.)

LAIR POWERS:

• The aboleth casts phantasmal force (no components required) on any number of creatures it can see within 60 feet of it. While maintaining concentration on this effect, the aboleth can't take other lair actions. If a target succeeds on the saving throw or if the effect ends for it, the target is immune to the aboleth's phantasmal force lair action for the next 24 hours, although such a creature can choose to be affected.
• Pools of water within 90 feet of the aboleth surge outward in a grasping tide. Any creature on the ground within 20 feet of such a pool must succeed on a DC 14 Strength saving throw or be pulled up to 20 feet into the water and knocked prone. The aboleth can't use this lair action again until it has used a different one.
• Water in the aboleth's lair magically becomes a conduit for the creature's rage. The aboleth can target any number of creatures it can see in such water within 90 feet of it. A target must succeed on a DC 14 Wisdom saving throw or take 7 (2d6) psychic damage. The aboleth can't use this lair action again until it has used a different one.
• A 50-foot square area of ground within 120 feet of the beholder becomes slimy; that area is difficult terrain until initiative count 20 on the next round.
• Walls within 120 feet of the beholder sprout grasping appendages until initiative count 20 on the round after next. Each creature of the beholder's choice that starts its turn within 10 feet of such a wall must succeed on a DC 15 Dexterity saving throw or be grappled. Escaping requires a successful DC 15 Strength (Athletics) or Dexterity (Acrobatics) check.
• An eye opens on a solid surface within 60 feet of the beholder. One random eye ray of the beholder shoots from that eye at a target of the beholder's choice that it can see. The eye then closes and disappears.
• An area that is a 50-foot cube within 120 feet of the tyrant is filled with spectral eyes and tentacles. To creatures other than the death tyrant, that area is lightly obscured and difficult terrain until initiative count 20 on the next round.
• Walls sprout spectral appendages until initiative count 20 on the round after next. Any creature, including one on the Ethereal Plane, that is hostile to the tyrant and starts its turn within 10 feet of a wall must succeed on a DC 17 Dexterity saving throw or be grappled. Escaping requires a successful DC 17 Strength (Athletics) or Dexterity (Acrobatics) check.
• A spectral eye opens in the air at a point within 50 feet of the tyrant. One random eye ray of the tyrant shoots from that eye, which is considered to be an ethereal source, at a target of the tyrant's choice. The eye then closes and disappears.
• The tomb trembles violently for a moment. Each creature on the floor of the tomb must succeed on a DC 19 Dexterity saving throw or be knocked prone.
• The demilich targets one creature it can see within 60 feet of it. An antimagic field fills the space of the target, moving with it until initiative count 20 on the next round.
• The demilich targets any number of creatures it can see within 30 feet of it. No target can regain hit points until initiative count 20 on the next round.
• Pools of water that the dragon can see within 120 feet of it surge outward in a grasping tide. Any creature on the ground within 20 feet of such a pool must succeed on a DC 15 Strength saving throw or be pulled up to 20 feet into the water and knocked prone.
• A cloud of swarming insects fills a 20-foot-radius sphere centered on a point the dragon chooses within 120 feet of it. The cloud spreads around corners and remains until the dragon dismisses it as an action, uses this lair action again, or dies. The cloud is lightly obscured. Any creature in the cloud when it appears must make on a DC 15 Constitution saving throw, taking 10 (3d6) piercing damage on a failed save, or half as much damage on a successful one. A creature that ends its turn in the cloud takes 10 (3d6) piercing damage.
• Magical darkness spreads from a point the dragon chooses within 60 feet of it, filling a 15-foot-radius sphere until the dragon dismisses it as an action, uses this lair action again, or dies. The darkness spreads around corners. A creature with darkvision can't see through this darkness, and nonmagicallight can't illuminate it. If any of the effect's area overlaps with an area of light created by a spell of 2nd level or lower, the spell that created the light is dispelled.
• Part of the ceiling collapses above one creature that the dragon can see within 120 feet of it. The creature must succeed on a DC 15 Dexterity saving throw or take 10 (3d6) bludgeoning damage and be knocked prone and buried. The buried target is restrained and unable to breathe or stand up. A creature can take an action to make a DC 10 Strength check, ending the buried state on a success.
• A cloud of sand swirls about in a 20-foot-radius sphere centered on a point the dragon can see within 120 feet of it. The cloud spreads around corners. Each creature in the cloud must succeed on a DC ls''constitution saving throw or be blinded for 1 minute. A creature can repeat the saving throw at the ertd of each of its turns, ending the effect on itself on a success.
• Lightning arcs, forming a 5-foot-wide line between two of the lair's solid surfaces that the dragon can see. They must be within 120 feet of the dragon and 120 feet of each other. Each creature in that line must succeed on a DC 15 Dexterity saving throw or take 10 (3d6) lightning damage.
• Grasping roots and vines erupt in a 20-foot radius centered on a point on the ground that the dragon can see within 120 feet of it. That area becomes difficult terrain, and each creature there must succeed on a DC 15 Strength saving throw or be restrained by the roots and vines. A creature can be freed if it or another creature takes an action to make a DC 15 Strength check and succeeds. The roots and vines wilt away when the dragon uses this lair action again or when the dragon dies.
• A wall of tangled brush bristling with thorns springs into existence on a solid surface within 120 feet of the dragon. The wall is up to 60 feet long, 10 feet high, and 5 feet thick, and it blocks line of sight. When the wall appears, each creature in its area must make a DC 15 Dexterity saving throw. A creature that fails the save takes 18 (4d8) piercing damage and is pushed 5 feet out of the wall's space, appearing on whichever side of the wall it wants. A creature can move through the wall, albeit slowly and painfully. For every 1 foot a creature travels through the wall, it must spend 4 feet of movement. Furthermore, a creature in the wall's space must make a DC 15 Dexterity saving throw once each round it's in contact with the wall, taking 18 (4d8) piercing damage on a failed save, or half as much damage on a successful one. Each 10-foot section of wall has AC 5, 15 hit points, vulnerability to fire damage, resistance to bludgeoning and piercing damage, and immunity to psychic damage. The wall sinks back into the ground when the dragon uses this lair action again or when the dragon dies.
• Magical fog billows around one creature the dragon can see within 120 feet of it. The creature must succeed on a DC 15 Wisdom saving throw or be charmed by the dragon until initiative count 20 on the next round.
• Magma erupts from a point on the ground the dragon can see within 120 feet of it, creating a 20-foot-high, 5-foot-radius geyser. Each creature in the geyser's area must make a DC 15 Dexterity saving throw, taking 21 (6d6) fire damage on a failed save, or half as much damage on a successful one.
• A tremor shakes the lair in a 60-foot radius around the dragon. Each creature other than the dragon on the ground in that area must succeed on a DC 15 Dexterity saving throw or be knocked prone.
• Volcanic gases form a cloud in a 20-foot-radius sphere centered on a point the dragon can see within 120 feet of it. The sphere spreads a round corners, and its area is lightly obscured. It lasts until initiative count 20 on the next round. Each creature that starts its turn in the cloud must succeed on a DC 13 Constitution saving throw or be poisoned until the end of its turn. While poisoned in this way, a creature is incapacitated.
• Freezing fog fills a 20-foot-radius sphere centered on a point the dragon can see within 120 feet of it. The fog spreads around corners, and its area is heavily obscured. Each creature in the fog when it appears must make a DC 10 Constitution saving throw, taking 10 (3d6) cold damage on a failed save, or half as much damage on a successful one. A creature that ends its turn in the fog takes 10 (3d6) cold damage. A wind of at least 20 miles per hour disperses the fog. The fog otherwise lasts until the dragon uses this lair action again or until the dragon dies.
• Jagged ice shards fall from the ceiling, striking up to three creatures underneath that the dragon can see within 120 feet of it. The dragon makes one ranged attack roll (+7 to hit) against each target. On a hit, the target takes 10 (3d6) piercing damage.
• The dragon creates an opaque wall of ice on a solid surface it can see within 120 feet of it. The wall can be up to 30 feet long, 30 feet high, and 1 foot thick. When the wall appears, each creature within its area is pushed 5 feet out of the wall's space; appearing on whichever side of the wall it wants. Each 10-foot section of the wall has AC 5, 30 hit points, vulnerability to fire damage, and immunity to acid, cold, necrotic, poison, and psychic damage. The wall disappears when the dragon uses this lair action again or when the dragon dies.
• A strong wind blows around the dragon. Each creature within 60 feet of the dragon must succeed on a DC 15 Strength saving throw or be pushed 15 feet away from the dragon and knocked prone. Gases and vapors are dispersed by the wind, and unprotected flames are extinguished. Protected flames; such as lanterns, have a 50 percent chance of being extinguished.
• A cloud of sand swirls about in a 20-foot-radius sphere centered on a point the dragon can see within 120 feet of it. The cloud spreads around corners. Each creature in it must succeed on a DC 15 Constitution saving throw or be blinded for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.
• The dragon creates fog as though it had cast the fog cloud spell. The fog lasts until initiative count 20 on the next round.
• A thunderclap originates at a point the dragon can see within 120 feet of it. Each creature within a 20-foot radius centered on that point must make a DC 15 Constitution saving throw or take 5 (1d10) thunder damage and be deafened until the end of its next turn.
• The dragon chooses a point on the ground that it can see within 120 feet of it. Stone spikes sprout from the ground in a 20-foot radius centered on that point. The effect is otherwise identical to the spike growth spell and lasts until the dragon uses this lair action again or until the dragon dies.
• The dragon chooses a 10-foot-square area on the ground that it can see within 120 feet of it. The ground in that area turns into 3-foot-deep mud. Each creature on the ground in that area when the mud appears must succeed on a DC 15 Dexterity saving throw or sink into the mud and become restrained. A creature can take an action to attempt a DC 15 Strength check, freeing itself or another creature within its reach and ending the restrained condition on a success. Moving 1 foot in the mud costs 2 feet of movement. On initiative count 20 on the next round, the mud hardens, and the Strength DC to work free increases to 20.
• The dragon glimpses the future, so it has advantage on attack rolls, ability checks, and saving throws until initiative count 20 on the next round.
• One creature the dragon can see within 120 feet of it must succeed on a DC 15 Charisma saving throw or be banished to a dream plane, a different plane of existence the dragon has imagined into being. To escape, the creature must use its action to make a Charisma check contested by the dragon's. If the creature wins, il' escapes the dream plane. Otherwise, the effect ends on initiative count 20 on the next round. When the effect ends, the creature reappears in the space it left or in the nearest unoccupied space if that one is occupied.
• The dragon creates fog as if it had cast the fog cloud spell. The fog lasts until initiative count 20 on the next round.
• A blistering cold wind blows through the lait the dr.a gon•, Jiilach creature within 120 feet ofthe  dragon must succeed on a DC 15 Constitution saving throw or take 5 (1dl0) cold damage. Gases and vapors are dispersed by the wind, and unprotected flames are extinguished. Protected flames, such as lanterns, have a 50 percent chance of being extinguished.
• A strong current moves through the kraken's lair. Each creature within 60 feet of the kraken must succeed on a DC 23 Strength saving throw or be pushed up to 60 feet away from the kraken. On a success, the creature is pushed 10 feet away from the kraken.
• Creatures in the water within 60 feet of the kraken have vulnerability to lightning damage until initiative count 20 on the next round.
• The water in the kraken's lair becomes electrically charged. All creatures within 120 feet of the kraken must succeed on a DC 23 Constitution saving throw, taking 10 (3d6) lightning damage on a failed save, or half as much damage on a successful one.
• The lich rolls a d8 and regains a spell slot of that level or lower. If it has no spent spell slots of that level or lower, nothing happens.
• The lich targets one creature it can see within 30 feet of it. A crackling cord of negative energy tethers the lich to the target. Whenever the lich takes damage, the target must make a DC 18 Constitution saving throw. On a failed save, the lich takes half the damage (rounded down), and the target takes the remaining damage. This tether lasts until initiative count 20 on the next round or until the lich or the target is no longer in the lich's lair.
• The lich calls forth the spirits of creatures that died in its lair. These apparitions materialize and attack one creature that the lich can see within 60 feet of it. The target must succeed on a DC 18 Constitution saving throw, taking 52 (15d6) necrotic damage on a failed save, or half as much damage on a success. The apparitions then disappear.
• Each undead creature in the lair can pinpoint the location of each living creature within 120 feet of it until initiative count 20 on the next round.
• Each undead in the lair has advantage on saving throws against effects that turn undead until initiative count 20 on the next round.
• Until initiative count 20 on the next round, any non-undead creature that tries to cast a spell of 4th level or lower in the mummy lord's lair is wracked with pain. The creature can choose another action, but if it tries to cast the spell, it must make a DC 16 Constitution saving throw. On a failed save, it takes ld6 necrotic damage per level of the spell, and the spell has no effect and is wasted.
• The flow of time is altered such that every creature in the lair must reroll initiative. The sphinx can choose not to reroll.
• The effects of time are altered such that every creature in the lair must succeed on a DC 15 Constitution saving throw or become 1d20 years older or younger (the sphinx's choice), but never any younger than 1 year old. A greater restoration spell can restore a creature's age to normal.
• The flow of time within the lair is altered such that everything within moves up to 10 years forward or backward (sphinx's choice). Only the sphinx is immediately aware of the time change. A wish spell can return the caster and up to seven other creatures designated by the caster to their normal time.
• The sphinx shifts itself and up to seven other creatures it can see within in its lair to another plane of existence. Once outside its lair, the sphinx can't use lair actions, but it can return to its lair as a bonus action on its turn, taking up to seven creatures with it

LAIR EFFECTS

• Underground surfaces within 1 mile of the aboleth's lair are slimy and wet and are difficult terrain.
• Water sources within 1 mile of the lair are supernaturally fouled. Enemies of the aboleth that drink such water vomit it within minutes.
• As an action, the aboleth can create an illusory image of itself within 1 mile of the lair. The copy can appear at any location the aboleth has seen before or in any location a creature charmed by the aboleth can currently see. Once created, the image lasts for as long as the aboleth maintains concentration, as if concentrating on a spell. Although the image is intangible, it looks, sounds, and can move like the aboleth. The aboleth can sense, speak, and use telepathy from the image's position as if present at that position. If the image takes any damage, it disappears.
• Creatures within 1 mile of the beholder's lair sometimes feel as if they're being watched when they aren't.
• When the beholder sleeps, minor warps in reality occur within 1 mi1e of its lair and then vanish 24 hours later. Marks on cave walls might change subtly, an eerie trinket might appear where none existed before harmless slime might coat a statue, and so on. These effects apply only to natural surfaces and to nonmagical objects that aren't on anyone's person.
• When a creature hostile to the tyrant and aware of its existence finishes a long rest within 1 mile of the tyrant's lair, roll a d20 for that creature. On a roll of 10 or lower, the creature is subjected to one random eye · ray of the tyrant.
• The first time a non-evil creature enters the tomb's area, the creature takes 16 (3d10) necrotic damage.
• Monsters in the tomb have advantage on saving throws against being charmed or frightened, and ag!linst features that turn undead.
• The tomb is warded against the magical travel of creatures the demilich hasn't authorized. Such creatures can't teleport into or out of the tomb's area or use planar travel to enter or leave it. Effects that allow teleportation or planar travel work within the tomb as long as they aren't used to leave or enter the tomb's area.
• The land within 6 miles of the lair takes twice as long as normal to traverse, since the plants grow thick and twisted, and the swamps are thick with reeking mud.
• Water sources within 1 mile of the lair are supernaturally fouled. Enemies of the dragon that drink such water regurgitate it within minutes.
• Fog lightly obscures the land within 6 miles of the lair.
• Thunderstorms rage within 6 miles of the lair.
• Dust devils scour the land within 6 miles of the lair. A dust devil has the statistics of an air elemental, but it can't fly, has a speed of 50 feet, and has an Intelligence and Charisma of 1 (- 5).
• Hidden sinkholes form in and around the dragon's lair. A sinkhole can be spotted from a safe distance with a successful DC 20 Wisdom (Perception) check. Otherwise, the first creature to step on the thin crust covering the sinkhole must succeed on a DC 15 Dexterity saving throw or fall 1d6 x 10 feet into the sinkhole.
• Thickets form labyrinthine passages within 1 mile of the dragon's lair. The thickets act as 10-foot-high, 10-foot-thick walls that block line of sight. Creatures can move through the thickets, with every 1 foot a creature moves costing it 4 feet of 15 Dexterity saving throw once each round it's in contact with the 'thickets or take 3 (1d6) piercing damage from thorns. Each 10-foot-cube of thickets has AC 5, 30 hit points, resistance to bludgeoning and piercing damage, vulnerability to fire damage, and immunity to psychic and thunder damage.
• Within 1 mile of its lair, the dragon leaves no physical evidence of its passage unless it wishes to. Tracking it there is impossible except by magical means. In addition, it ignores movement impediments and damage from plants in this area that are neither magical nor creatures, including the thickets described above. The plants remove themselves from the dragon's path.
• Rodents and birds within 1 mile of the dragon's lair serve as the dragon's eyes and ears. Deer and other large game are strangely absent, hinting at the presence of an unnaturally hungry predator.
• Small earthquakes are common within 6 miles of the dragon's lair.
• Water sources within 1 mile of the lair are supernaturally warm and tainted by sulfur.
• Rocky fissures within 1 mile of the dragon's lair form portals to the Elemental Plane of Fire, allowing creatures of elemental fire into the world to dwell nearby.
• Chilly fog lightly obscures the land within 6 miles of the dragon's lair.
• Freezing precipitation falls within 6 miles of the dragon's lair, sometimes forming blizzard conditions when the dragon is at rest.
• Icy walls block off areas in the dragon's lair. Each wall is 6 inches thick, and a 10-foot section has AC 5, 15 hit points, vulnerability to fire damage, and immunity to acid, cold, necrotic, poison, and psychic damage. If the dragon wishes to move through a wall, it can do so without slowing down. The portion of the wall the dragon moves through is destroyed, however.
• Tracks appear in the sand within 6 miles of the dragon's lair. The tracks lead to safe shelters and hidden water sources, while also leading away from areas that the dragon prefers to remain undisturbed.
• Images of Large or smaller monsters haunt the desert sands within 1 mile of the dragon's lair. These illusions move and appear real, although they can do no harm. A creature that examines an image from a distance can tell it's an illusion with a successful DC 20 Intelligence (Investigation) check. Any physical interaction with an image reveals it to be an illusion, because objects pass through it.
• Whenever a creature with an Intelligence of 3 or higher comes within 30 feet of a water source within 1 mile of the dragon's lair, the dragon becomes aware of the creature's presence and location.
• Once per day, the dragon can alter the weather in a 6-mile radius centered on its lair. The dragon doesn't need to be outdoors; otherwise the effect is identical to the control weather spell.
• Underwater plants within 6 miles of the dragon's lair take on dazzlingly brilliant hues.
• Within its lair, the dragon can set illusory sounds, such as soft music and strange echoes, so that they can be heard in various parts of the lair.
• Magic carvings of the dragon's smiling visage can be seen worked into stone terrain and objects within 6 miles of the dragon's lair.
• Tiny beasts such as rodents and birds that are normally unable to speak gain the magical ability to speak and understand Draconic while within 1 mile of the dragon's lair. These creatures speak well of the dragon, but can't divulge its whereabouts.
• Intelligent creatures within 1 mile of the dragon's lair are prone to fits of giggling. Even serious matters suddenly seem amusing.
• Whenever a creature that can understand a language sleeps or enters a state of trance or reverie within 6 miles of the dragon's lair, the dragon can establish telepathic contact with that creature and converse with it in its dreams. The creature remembers its ·~onversation with the dragon upon waking.'
• Banks of beautiful, opalescent mist manifest within 6 miles of the dragon's lair. The mist doesn't ,obscu~e anything. It assumes haunting forms when ev.il cveatures are near the dragon or other non-evil cn~attires in the mist, warning such creatures of the danger.
• Gems and pearls within 1 mile of the dragon's · lair sparkle and gleam, shedding dim light in a 5-foot radius.
• Once per day, the dragon can alter the weather in a 6-mile radius centered on its lair. The dragon doesn't need to be outdoors; otherwise the effect is identical to the control weather spell.
• Within 1 mile of the lair, winds buoy non-evil creatures that fall due to no act of the dragon's or its allies. Such creatures descend at a rate of 60 feet per round and take no falling damage.
• Given days or longer to work, the dragon can make clouds and fog within its lair as solid as stone, forming structures and other objects as it wishes.
• The kraken can alter the weather at will in a 6-mile radius centered on its lair. The effect is identical to the control weather spell.
• Water elementals coalesce within 6 miles of the lair. These elementals can't leave the water and have Intelligence and Charisma scores of 1 (- 5).
• Aquatic creatures within 6 miles of the lair that have an Intelligence score of 2 or lower are charmed by the kraken and aggressive toward intruders in the area.
• Food instantly molders and water instantly evaporates when brought into the lair. Other non magical drinks are spoiled- wine turning to vinegar, for instance.
• Divination spells cast within the lair by creatures other than the mummy lord have a 25 percent chance to provide misleading results, as determined by the DM. If a divination spell already has a chance to fail or become unreliable when cast multiple times,·t11at chance increases by 25 percent.
• A creature that takes treasure from the lair is cursed until the treasure is returned. The cursed target has disadvantage on all saving throws. The curse lasts until removed by a remove curse spell or other magi~. ·
• Open flames of a non magical nature are extinguished within the unicorn's domain. Torches and campfires refuse to burn, but closed lanterns are unaffected.
• Creatures native to the unicorn's domain have an easier time hiding; they have advantage on all Dexterity (Stealth) checks made to hide.
• When a good-aligned creature casts a spell or uses a magical effect that causes another good-aligned creature to regain hit points, the target regains the maximum number of hit points possible for the spell or effect.
• Curses affecting any good-aligned creature are suppressed.
• There's a noticeable increase in the populations of bats, rats, and wolves in the region.
• Plants within 500 feet of the lair wither, and their stems and branches become twisted and thorny.
• Shadows cast within 500 feet of the lair seem abnormally gaunt and sometimes move as though alive.
• A creeping fog clings to the ground within 500 feet of the vampire's la ir. The fog occasionally takes eerie forms, such as grasping claws and writhing serpents.