Originally Posted by
gracfuldeath
I feel like I've noticed this sometimes, but maybe with the felhunter. iirc, I just clicked it to make him cast it, and he went on auto casting it as he should have.
Make sure he's actually set to attack as well, and not just standing next to the boss with you.
More importantly,...why do you have the felguard out after the first 7-8s of the fights? Once he charges in, you pop his felstorm and your DS:Felguard, then the moment the felstorm ends you switch to the felhunter, meaning he'll using legion strike maybe twice. If you're using MWC, and hardcast summoning him, it's pretty much the same thing, pop felstorm/DS, felstorm ends and summon the felhunter.