I'm not sure why people are trying to figure out an appropriate penalty for Living Dead. Hallowed Ground doesn't have a penalty. It just has you ignore damage. It's powerful. It makes you feel good for using it. The recast isn't a penalty either. Invulns should be on a 5-7 minute recast at the very minimum. That's just good design.

Holmgang doesn't actually have a penalty. It prevents knockback. It has a stupidly low recast, to the point of being one of the single most broken abilities in the game. It's powerful. It feels good to use.

So why should we settle for having to have healers burn their cooldowns to save us from Living Dead? Simply for the privilege of doing what other tanks can do in their sleep? I'm sorry, but it's not acceptable.

If you want Living Dead to actually represent a "middle ground" between Hallowed and Holmgang, then two things must happen. First, you need a full 10 seconds of invulnerability, regardless of what happens. Second, when you hit 1 HP, you need some sort of a self-healing effect, either through your own attacks or your enemies', which starts making your HP tick back up. That's the middle ground between negating damage and preventing death. Stop penalising us for using our ultimate ability, and let it actually feel good to use.

And either way, there is no reason why Holmgang should be less than five minutes. The existence of a three minute recast invincibility is why progression raiders are laughing their way through your tankbusters. Stop trivialising the content.