Ultranium/Heart of Erebus

Heart of Erebus is a post-Moon Lord Expert Mode-exclusive that is obtained from '. When equipped, you will receive immunity to the, +60 maximum health and +30 max mana, and bonus buffs as the player's health gets lower that stack. The bonus buffs are as follow:
 * 15% increased critical strike chance when below 75% health.
 * 15% increased damage below 50% health.
 * 15 defense below 25% health.