Defiance should have a selfheal component based on damage dealt.
Unchained should have a 40 sec cooldown.
Cyclone should have an enmity component.
Mercy Stroke should heal for 10 percent of health when used, 20 if it kills the enemy.
They need to introduce a new ability that heals you for x amount of the damage taken over the last x seconds. Don't know how long the cool down should be.