Death Knight

The Death Knights, formidable warriors in servitude and worship to Thanatos, exude an aura of darkness on the battlefield. With a chilling resolve, they strike terror into the hearts of their foes, embodying the relentless pursuit of death. Their allegiance to Thanatos makes them formidable and relentless adversaries, embracing the inevitability of death with each menacing step.

Death Comes, Unexpectedly

Starting at 3rd level, Thanatos has granted the Fighter the ability to transport to the dead. Gain access to "Death Comes, Unexpectedly" as a bonus action. Once per short rest, use "Death Comes, Unexpectedly" to teleport to any corpse within sight, dealing 1d6 necrotic damage to all surrounding enemies.

Thanatonian Vengeance

Starting at 7th level, Death Knight can use "Your time has come" as a bonus action. "Your time has come" can be used once per short rest. "Your time has come" marks an enemy, "Death Comes, Unexpectedly" can be used on marked creature even if not dead, any roll made against the marked creature is made with advantage, and any successful melee attacks made against the creature deals an additional 1d10 necrotic damage. Additionally, all rolls made against Undead creatures are made with advantage, and Undead creatures take an additional 2d6 Necrotic damage from successful melee attacks. 

Thanatonian Weapon

Starting at 10th level, Death Knight can pact to one weapon to become a "Thanatonian Weapon". Thanatonian Weapon returns to Death Knight when thrown or lost, and deals additional 2d6 Necrotic Damage. Thanatonian Weapon also cannot be broken and deals an additional 4d6 damage to Undead creatures.

Death doesn't stop

Starting at 15th level, any time Death Knight kills a creature, regain an action and a bonus action. This can happen multiple times in one turn.

Memento Mori

Starting at 18th level, Death Knight can summon an Apparition of Thanatos as a friendly creature. Apparition of Thanatos moves constantly towards hostile creature with least HP and deals 4d12+5 damage with Scythe Attack (10ft).