Hm... Tough call... I'd probably be a side character that gets 1 backstory episode but then everyone forgets about him. Plus I know it's unrelated but I'm sure it's been done, but if I were a character my magic would be Identification Magic. Anyone need to know something about an item? Just ask me to identify it.
I'm thinking of going with Mavis, I'm a bit childish but can be serious some time as well... Hmm, but Zeref's a good one too, well if you ignore his evil side... But I also like Levy, I can relate much with her naivety and love for books.