Well, the title should be self explanatory.
I really, REALLY didn't enjoy having to deal with this mechanic.
As a premise, just to be clear, this is not a complaint about "excessive difficulty".
I already beaten all the encounters I've crossed up to this point where this ability was used and it wasn't even that much of a struggle once I stopped the first time to read what it did and what I was supposed to do.
It's just that the mechanic itself (that as far as I'm aware is NOT a D&D thing by any stretch) is spectacularly unenjoyable. The annoyance in having to waste a certain amount of hits on these characters before any other action with any meaning can be performed on them reminded me of the infamous DOS 2 armor system.
Hell, in some way it's actually worse, since you could at least OUT-DPR that one, while with this is just rolling your eyes and wasting a bunch of attacks to "get to the point".