K'zrath by Meemaster

K'zrath's attacks and some abilities apply Maddening Whispers to enemies, causing them to take damage equal to 1% of their maximum health over 10 seconds. Maddening Whispers can stack with itself up to 10 times, with each new stack having its own duration.
Allied Heroes in a large radius around an enemy affected by Maddening Whispers regain health equal to 25% of the damage dealt if its a Minion and 50% of the damage dealt if its a Hero.
In addition, allied Heroes regain health equal to 20% of the damage they deal to enemy Heroes affected by Maddening Whispers.

K'zrath deals 52 damage to all enemies affected by Maddening Whispers and adds a stack of Maddening Whispers to enemies near him.

K'zrath chooses an enemy Hero, and, after 3 seconds, they erupt in a flurry of poisoned blades, dealing 84 damage to enemies near them and applying a stack of Maddening Whispers to them.
The enemy team knows when a Hero is targeted by Systematic Betrayal, similar to Kael'thas' Living Bomb.

K'zrath incites panic in himself or an allied Hero, increasing their movement speed and attack speed by 15% for 3 seconds.

Teleport to an allied Hero or a Hero affected by Maddening Whispers and become Invisible for 2 seconds or until dealing or taking damage.

For 4 seconds, enemy Heroes affected by Maddening Whispers take 100% of the damage they deal.

K'zrath and a chosen allied Hero become invisible to enemies affected by Maddening Whispers for 8 seconds, and their attack speeds are increased by 10%.