Doom Blade

On a hit with a melee attack, you deal 2d10
Necrotic damage. A creature hit by Doom Blade
cannot heal until the start of the target's next turn
and if the target is reduced to 10 hit points or less
after damage is resolved, the creature dies.
At Level 5: 4d10 Necrotic. Level 11: 6d10 Necrotic. Level 17: 10d10 Necrotic Damage and the death threshold increases to 30 HP.