Having been spending some time on my shammy and DK, I came back to my warlock and tried to continue contributing to damage mitigation by interrupting targets. But I'm having some trouble, it may be my brain isn't working completely. Overall, do we have any actual interrupts, in the sense of abilities that will interrupt even if the target is immune to the primary effect of the ability?
I can't remember if FG Intercept did interrupt on targets that were stun-immune, but have confirmed that Axe Toss does not. The glyphed HoG effect doesn't interrupt either, as far as I can tell. The fear and horror effects are similarly confined to targets that are not fear-immune. Whiplash?
Seems like you're Demonology, but in any case, Affliction locks have the Felhunter's Spell Lock. Works most of the time (if not always).