Devilish Heritages

You learn how to adapt the abilities of monster you have slain. You can gain increased speed, devilish wings or even magic like dominating monster trough innate power.

Devil

If you kill a devil you adapt an ability of that devil.

Barbed Devil

If you kill a Barbed Devil you gain Barbed Hide: At the start of each of its turns, the barbed devil deals 5 (1d10) piercing damage to any creature grappling it.l

Bearded Devil

If you kill a Bearded Devil you gain devil's sight, magical darkness doesn't impede the devil's darkvision.

Bone Devil

If you kill a Bone Devil you gain magic resistance, you have advantage on saving throws against spells and other magical effects.

Chain Devil

If you kill a Chain Devil you gain immunity to fire damage

Erinyes

If you kill a Erinyes you gain Hellish Weapons. Your weapon attacks are magical and deal an extra (3d8) poison damage on a hit.

Horned Devil

If you kill a Horned Devil your horn grows and you gain devil wings and a fly speed of 60 ft.

Ice Devil

If you kill a Ice Devil you gain immunity to ice damage

Imp

If you kill a Imp you gain immunity to poison damage

Lemure

If you kill a Lemure you gain immunity to beign charmed.

Pit Fiend

If you kill a Pit Fiend you gain the ability to cast fireball at will

Spined Devil

If you kill a Spinned Devil, you gain the ability to speak trough telepathy within 120 ft.

Demon

If you kill a demon you adapt an ability of that demon.

Balgura

If you kill a Balgura you gain Reckless.

Reckless. At the start of its turn, you can gain advantage on all melee weapon attack rolls it makes during that turn, but attack rolls against it have advantage until the start of its next turn.

Balor

If you kill a Balor you gain Fire Aura.

Fire Aura. At the start of each of your turns, each creature within 5 feet of it takes 10 (3d6) fire damage, and flammable objects in the aura that aren't being worn or carried ignite. A creature that touches you or hits it with a melee attack while within 5 feet of it takes 10 (3d6) fire damage.

Chasme

If you kill a Chasme you gain Spider Climb

Spider Climb. You can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

Dretch

If you kill a Dretch you gain resistance to lightning damage.

Glabrezu

If you kill a Glabrezu you gain the ability to cast dispel magic at will

Goristro

If you kill a Goristro you gain Labyrinthine Recall.

Labyrinthine Recall. You can perfectly recall any path you have traveled.

Hezrou

If you kill a Hezrou you gain resistance to Bludgeoning, Piercing, and Slashing from Nonmagical Attacks

Manes

f you kill a Manes you gain immunity to beign frightened.

Marilith

If you kill a Marilith you gain 4 additional arms that are attached below your armpit, two on each side.

Multiattack. You gain 4 extra attacks. You can make an attack with each of your six arm as long as you supply one weapon in each hand. You can only make two unarmed strikes though.

Nalfeshnee

If you kill a Nalfeshnee gain you can magically teleport, along with any equipment it is wearing or carrying, up to 120 feet to an unoccupied space it can see.

Quasit

If you kill a Quasit your movement speed increases by 10ft

Shadow Demon

If you kill a Shadow Demon you gain immunity to beign exhaustion.

Vrock

If you kill a Vrock you gain sharp talons on your hands.

Talons.  When you make an unarmed strike you deal 2d10 slashing damage.

Yochlol

If you kill a Yochlol you gain the ability to cast web at will requiring no material components.

Adapt

Whenever you kill something you gain 10 temporary hit points.

Killing Fury

When you kill a creature you gain + 1d6 of the weapons damage type to your melee weapon attacks for the next 10 minutes. You can benefit only from this feature once but they do stack in time. 

Devil Form

You can use your bonus action to turn into a infernal lord and for a minute you gain the following benefits:
All your attacks deal an additional 1d12 fire damage
You gain advantage on all charisma checks and saving throws
Your weapons turn into longswords that look like a trident blade with a military fork as a hilt