I hadn't considered awkward unintended resistance synergy, totally makes sense. I really like the idea of separating it out as a new buff.
The debuff he leaves behind is definitely a consideration too though since shatterpoint application is, again, random. Seems like daze could be incredibly useful against portions of a squad and then not at all useful against others. Maybe a debuff more universally useful, like offense down?
I realize the randomness levels out at the end, and it is purposefully part of his kit, but I just feel like randomness is also a big part of why he gets left on the bench as well.
But that's just nitpicky, overall this is a great idea. I like it.