Is Hero's Will glitched?

I was at Horntail today and got seduced. I spammed my Hero's Will key after I got 1/1d to try and survive but Hero's Will did not activate. I've noticed that this has happened before to at random times. During the Horntail run I went on earlier Hero's Will worked fine so I can't figure out what's going on with it. Any insight? Thanks.

I know that the skill was broken and not working for awhile, but that supposedly was fixed a while ago. Of course old bugs resurfacing is something that's not new.


Edit: or you just needed some mp

Hero's Will uses MP.

Well, I'm a complete idiot. I don't know why I thought it didn't use MP. Thanks a lot.