Very cool-looking for sure, but not the most powerful. Ulquiorra said himself he opted for better regenerative powers, rather than destructive ones. Obviously still insanely powerful nonetheless.
Yeah, that's the only name given to it. Most of the attacks in DB don't have official names, and only recieved them from the games.
From Bleach, I personally love the Getsuga Tenshou, and Baraggan's Respira attack.