Lifedrainer

Your patron has responded to your will to seek power and has given you the ability to drain life essence. As you gain more power, it does as well. 

Expanded Spell List

The Lifedrainer lets you choose from an expanded list of spells when you learn a warlock spell. The following spells are added to the warlock spell list for you.

Lifedrainer Expanded Spells

Life Drain

1st-level Lifedrainer feature

Starting at 1st level, you have a hunger that can only be quenched by life energy. As a bonus action, when you do damage to a creature with an attack or a spell you can siphon some of their life essence and make it your own. You do extra necrotic damage equal to half your warlock level rounded up + your Proficiency bonus + your Constitution modifier and gain temporary hit points equal to the damage dealt. If you hit with a critical, this extra damage is also critical.

You can use this ability a number of times equal to half your Proficiency bonus rounded down. You regain all uses of this ability after a short or long rest. 

As you and your patron drain more power, you gain the ability to dig deeper into your enemies' essence.
At 6th level, this ability ignores resistance to necrotic damage.
At 14th level, this ability cuts through any damage immunities or resistances.

Bloodthirsty

1st-level Lifedrainer feature

Your life-seeking patron grants you the strength to get up close and personal with your enemies. Starting at 1st level, you add can your Proficiency bonus to your AC when you're not wearing armor. If you have used your action to make a melee attack this turn, the creature or creatures you targeted have disadvantage on opportunity attacks against you until the start of your next turn. 

Life Casting

6th-level Lifedrainer feature

The Lifedrainer gives you the ability to gain power from another's life essence, but you can also sacrifice your own life essence for power. Starting at 6th level, you can use health to cast spells instead of spell slots. You must sacrifice health equal to 1d4 + the level that the spell is cast at. At 10th level you must sacrifice 1d6 + two times the level that the spell is cast. At 14th level you must sacrifice 1d8 + three times the level that the spell is cast. This damage may not be reduced in any way. You may use temporary hit points to fuel this ability. 

You can use this ability to cast spells at levels equal to or lower than that you have slots available, not higher. Mystic Arcanum slots are not eligible. Ex. At 7th level you can use this ability to cast a spell at 3rd level but not 5th level. 

You can use this ability a number of times equal to your proficiency bonus. You regain all uses of this feature after you finish a long rest.

High on Life

10th-level Lifedrainer feature

Starting at 10th level, you can strengthen yourself by stealing a creature's final moments. As a reaction, when a creature you can see reaches 0 hitpoints and dies, you can activate this ability and prepare to steal its dying shreds of life. You must get within 5 feet of the creature within 1 round of it dying for this ability to come into effect successfully (before what would be the start of its next turn). As you drain away its life the creature crumbles to dust, and for the next minute you gain the following abilities:

-You gain a +1 to your attack rolls and spell save DC.
-You have an advantage on Intelligence, Wisdom, and Charisma saving throws against spell effects.
-Your max hitpoints cannot be reduced in any way. 
-At the start of each of your turns, if you are conscious, you heal a number of hit points equal to 1d6 + your Constitution modifier. 
-You have advantage on death saving throws.

You can use this ability a number of times equal to half your Proficiency bonus rounded down. You regain all uses of this ability after a long rest.

At 18th level your ability also grants you these effects:
-You gain resistance to all damage types.
-You regain all uses of your Life Drain ability.

Ravenous

 14th-level Lifedrainer feature 

Starting at 14th level, you can drain life around you to keep yourself alive. When you would be reduced to 0 hitpoints, you are brought to 1 instead. Every creature you choose within a 30ft radius must make a Constitution saving throw against your spell save DC. They take necrotic damage equal to 2d8 + half your warlock level rounded up on a failed save and half that on a successful one. You regain hitpoints equal to the damage taken by every creature affected. Any creature within 5 feet of you fails the save automatically. If a creature has been affected by your Life Drain feature in the past 24 hours they have disadvantage on the save. 

Upon use of this ability, you gain the effects of your High on Life ability without costing a use of the ability. 

After you have used this ability you cannot do so again until after you finish a long rest. 

 At 18th level the range increases to 60ft and cuts through any damage immunities or resistances.