Death Knight

Warriors who answer the call of one of the Gods of Death become Death Knights. They commit to a deeply religious oath to become an emissary of death. They cover their faces with a death mask which can be used as a spellcasting focus. Becoming obsessed with death, the Death Knight will joyously end anyone living or undead to satisfy thier oath. Some can become so obsessed that they believe they must kill everything.

Spellcasting

Spellcasting

You can only learn spells from the Abjuration, Enchantment and Necromancy spell schools.

Cantrips 

You know 2 cantrips from the warlock spell list. At level 10 you know a 3rd cantrip.

Spell Slots

At level 3 you have one spell slot, and this is a first level spell slot.

You will receive an additional spell slot at levels 5, 11 and 17.

At level 7 your spell slots are second level.

At level 13 your spell slots are third level.

At level 19 your spell slots are fourth level.

Your spell slots refresh after a short or long rest.

Spells Known

You know 3 spells from the warlock spell list at level 3. You gain one additional spell at levels 9, and 15.

Spellcasting Ability

Charisma is your spell casting ability for your warlock spells. You use your Charisma whenever a spell refers to your spellcasting ability.

Spell save DC = 8 + proficiency bonus + Charisma mod

Spell attack mod = proficiency bonus + Charisma mod

Soulreaver

At 3rd level, when you reduce a hostile creature to 0 hit points you gain temporary hit points equal to your Charisma modifier + your fighter level.

Strength in the Face of Death

At 7th level, whenever a creature within 5 feet of the Death Knight is killed, the Death Knight can add it's Charisma mod to its attack and damage rolls in its next turn.

Death is not the end

At 10th level, when the Death Knight is reduced to 0 hit points, you can take a Charisma saving throw (DC 5 + damage taken). On a success, you instead drop to 1 hit point. This consumes one of your spell slots.

Call of the Grave

At level 15, when an attack roll is made against you, you can use your reaction and expend a spell slot to travel through the underworld, appearing in an empty space within 30 feet, avoiding the attack.

Doom

At level 18,  on a successful melee attack the Death Knight can mark a target for death. If that target has 100 or fewer hit points it dies instantly. If it has more than 100 hit points the mark remains for 3 turns and any attacks from the Death Knight that bring the target below 100 hit points, kills the target instantly.

This can be used once per short rest.