Oh wait, you mean using an ability to trigger to Rage, then finishing off ALL of Rage without a single auto-attack? That's... rather specific. I... don't know what happens with that. I'd assume that it'd still trigger on the next turn, but that sounds like a situation that could bug.

I have just noticed that quite a few randoms have realized that it happens as the "first action of Rage", and such, hold back from attacking until after Rage. And then the fuckers Trigger the shield when you're not expecting it since Rage ended ages ago and you waste a full fucking burst.