Passive: Mordekaiser stores 35% of the damage he deals and 15% of the damage he takes (reduced by 75% against non-champions) as energy on his secondary resource bar.

Active: Mordekaiser consumes the stored energy to grant himself a decaying shield for 4 seconds. The shield value is equal to 5-30% of Mordekaiser's maximum health, depending on how much energy he had stored.

After 0.25 seconds, Mordekaiser can re-cast this ability to consume the shield, healing himself for 40 / 42.5 / 45 / 47.5 / 50% of the remaining shield amount.