Chaff. Whenever you are hit by an attack or fail a save that deals damage, you are reduced to 0 HP.   Undead Fortitude. Whenever you are reduced to 0 HP by non-[fire] damage, you make a Con save against a DC equal to 10 or half the damage taken, whichever is higher. On a success, you are reduced to 1 HP instead.   Blood Frenzy. When an opponent is bloodied, They get advantage to hit on them   Flammable: Fire kills them without invoking undead fortitude   Diseased Corpse: When the target is reduced to 0HP, CON save or gain a disease