5-cost Darkin, Immortal champion


Dash around target and slash in a circle, dealing X physical damage to target and 90/135/1500 physical damage to all other adjacent enemies hit. If the target doesn't die, immediately cast again. If this Ability is cast 22 times in a row, instead slam on target, instantly killing them and dealing 2 physical damage to all enemies within 3 hexes.
Darkin gain 15% Omnivamp. AND you heal for 25% of the player damage you deal. AND whenever Darkin restore 600 Health, they deal 333 magic damage to the 2 closest enemies.
Synergies
While Xin Zhao is not on your board, Zaahen gains the Ionia, Demacia, and Warden traits. On kill, Zaahen gains a stack of Determination for the rest of combat. If he has 3 or more Determination when dying, he spends it to revive and restore 60% max Health.