Armlet of Mordiggian

Wondrous item, rare (requires attunement) While attuned, you can activate the Armlet of Mordiggian as a bonus action on your turn. While active, your Strength score increases by 4 (to a maximum of 24) and your AC increases by 1. At the end of each of your turns, you take 2d4 necrotic damage. This damage cannot be reduced or prevented, but you can't be reduced below 1 hit point this way. You can deactivate the Armlet as an action on a subsequent turn. Weapon of choice among brutes, the bearer sacrifices his life energy to gain immense strength and power.