The Lifedrinker

You struck a pact with a being that steals the life of others to fuel its magical abilities. Such creatures live to control their underlings and lead legions of thralls or zombies. They often are able to charm their underlings to follow them or simply be strong enough to force their underlings to submit to them. They plan to use the mortals that they bind to their servitude to be able to do what their normal underlings cannot and eventually turn on them to keep them from becoming a threat to their reign. They give the mortals that accept their pact raw magical power when they sacrifice their lifeforce to them.

Expanded Spell List

The Lifedrinker 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.

Lifedrinker Expanded Spells

Spell Level	Spells
1st	Burning Hands, Thunderwave
2nd	Flaming Sphere, Gust of Wind
3rd	Call Lightning, Wind Wall
4th	Wall of Fire, Ice Storm
5th	Flame Strike, Cone of Cold

Price for Power

Starting at 1st level you create your pact with your patron and they give you an artifact that can absorb your life. This can be many things such as a dagger or some other magical trinket. You can activate this trinket as a bonus action and it deals necrotic damage to you equal to your warlock level + your proficiency modifier (total damage minimum of 3). This damage cannot be resisted or negated by any means. After taking the damage, your patron gifts you with some of its raw magical power and you regain one of your Warlock spell slots.

If you want to regain a Mystic Arcanum charge, the damage increases by your proficiency modifier for each spell level above five that the Mystic Arcanum is. So if you want to regain the 7th level Mystic Arcanum, you would need to spend 28 health at 13th level.

The table below displays the damage taken at each level if you do not multiclass.

Damage Scaling

Lifesteal

Starting at 1st level you gain the ability to steal the life from your foes when you damage them with your Warlock spells, your patron's artifact must be in your possession for this ability to activate.

Different types of spells heal in different ways.

Cantrips heal you for 1 health no matter how much damage they deal nor the amount of foes that they damage unless they deal less damage than what they would heal for.

Area of effect spells such as Shatter heal for 2 health for each target hit that fails the saving throw. If they succeed and take damage you heal for 1 health, if they take no damage you do not heal. The healing amount maximizes at your warlock level. 

Single target spells that require a saving throw, such as Mind Spike heal for your warlock level if the target fails the saving throw and you heal for half of that (rounded up) if they succeed. You do not heal for more than the damage that you dealt to your target and if you deal 0 damage you do not heal.

Single target spells that require an attack roll heal the same as single target spells that require a saving throw, but if you miss your attack you do not heal.

A continuous spell like Hex or Summon Fey will heal for 1 health each time they take damage from the spell.

All static healing increases by 1 at 5th, 9th, 13th and 17th level. Cantrip healing increases by 1 at 5th and 13th level.

Regenerative Rest

Starting at 6th level, your patron wants you to sacrifice and steal the life from more enemies. You now regain two of your hit dice at the end of a short rest.

This increases to four at 10th level and six at 14th level.

Bloody Surprise

At 10th level, you can use your action to cause the blood or life force of your target to burst out of their bodies. You can use your action to cause your target to make a constitution saving throw if they fail take 5d8 necrotic damage as their blood erupts from their body if they succeed they take half damage.

You then can use the blood to regain a warlock spell slot or regain health equal to the amount of damage you would take from Price for Power at your current level. If they succeed the saving throw you regain half the damage you would take from Price for Power (rounded up). If they succeed you cannot regain a spell slot and if you do not deal enough damage to regain the health you can only regain health equal to the damage dealt.

You can use this ability once per short or long rest.

The damage increases to 6d8 at 14th level.

 Once you reach 15th level, your targets cannot resist necrotic damage from this ability however if they are immune to necrotic damage they take half damage.

This can be used on targets without blood.

Master of Life

At 14th level, as an action, you target a number of creatures equal to your Charisma modifier and begin to drain their life force for 1 minute. Your targets to make a Constitution saving throw at the start of their turn, if they fail the saving throw they take 2d8 necrotic damage. If they succeed the saving throw they take half. You also heal from all the damage that your targets take from this ability.

This ability is affected by concentration.

You can use this ability once per long rest.