Awaken Chaos Era Unhealable is a debuff that prevents the character from receiving healing effects. However, it does not prevent the character from replenishing their health through Life Steal. This ability is great against heroes who relies heavily on healing skills, heal spells or Revival Set to sustain themselves against enemies AoE nuke attacks.
Received healing effects are reduced by 100% [excludes Life Steal].
@A1: I have added Urzag to the Unhealable Hero list. Thanks!