I would perform... I don't know. It would be cool to just perform, like, charms and transfiguration as a whole, because I would like to levitate stuff, transform things into a pig... But jinxes and hexes are cool too... a single spell I would pick would be... maybe Legilimens... er, no, maybe... Imperio!... no, that's Dark Arts... I suppose some hex or something, I don't think any exact one would suffice right now. I would like to be able to perform one of those spells because it would be just awesome to, I don't know, maybe... use the Jelly-Legs Jinx or a Conjunctivious (sp?) Curse just for the sake of being able to do it!
Crucio - Latin for “to torture”. The Cruciatus Curse. This inflicts severe physical pain on whomever it is cast upon. To effectively use the Cruciatus Curse, the witch or wizard casting the spell must have the genuine desire to cause pain. When effectively used, the curse is excruciating and has the ability to drive victims insane. As such, it is one of the three Unforgivable Curses. The use of this spell against another human being is punishable by a life sentence in Azkaban.