As an Arrancar, Ulquiorra is supposedly the bad guy, but sometimes I can't tell which side he's on. Maybe it's just my bad sense, but I think his logic is a bit.....let's say different from the normal bad guys. Like how he spares the enemy if he doesn't have a reason to kill them..(when he spares Ichigo the first time he went to the real world). And another thing...he doesn't really do much if he isn't given specific order, unlike other Arrancars, who would do whatever to torture their prey. So does that mean he doesn't have the thirst to destroy?
Perhaps I'm thinking too much.
I'm really wondering what are the chances of him being non corrupted.