Unchained. Seriously, why are we not abusing this skill?

[Reynhart]

From that perspective, Unchained is one of the strongest defensive CDs in the game.

Considering that you should never be stanceless, Unchained is thus a Defensive cooldown that decreases your damage by 5% while locking your most powerful skill for slightly less than 25% increase in eHP.
So, basically, it's weaker than Rampart.

[Reynhart]

It doesn't lock out your most powerful skill because if you could read, you would've noticed that Unchained's duration lines-up with the amount of time needed to build another 5 stacks. If you are Infuriating while Unchained, you are doing it wrong.

But using those 5 stacks for Unchained prevents you from using Fell Cleave.

As for the healing bonus, you know that Defiance offers around the same eHP as Shield Oath thanks to the max HP increase and the healing bonus. And Shield Oath reduces damage like Rampart. So, a short time in Defiance...let's say, those 20s of Unchained, is exactly like being under Rampart for...20s. And it still reduces your DPS output by 5% just by forcing you out of Deliverance. And it also sits on a longer cooldown than Rampart.