Power Rings - How do?

[Thaal Sinestro]

Just need to know how far it can go. So like, can it go to the point where a single use leaves him completely drained, unable to move, but the attack is really really strong (for a non-super move)? 'Sinestro put more energy into each shot' could potentially mean up to that point, and I'd up it to 900 if that was the case.

The 900 point solution sounds about appropriate to me. Lanterns HAVE blasted with such strength that it's completely drained them or their rings.