Ah. I've only played Tales of Symphonia (Which I hate to admit, because there were several other Tales games that came before it but I only had a Nintendo GC at the time).
(nooooo why.... sorry, REALLY BIG WALL INCOMING)
"Oh you asked! I'm thrilled to introduce you the wise sorceress who travels the eleven seas, who scoffs at the might of dragons, none other than the acclaimed, the illustious Mazhigigika Miludin do Din Nolurun Dou, Magilou for short!"
Seriously she's great, I can say what I liked about her, although I'm not sure I can make her justice.
She's basically the mood maker of the group, she's easygoing and likes to make fun of others/turning what they say against them or in jokes, appearing kinda cruel at times. She's a bit theatrical/exaggerated at times, which is not appreciated by everyone (I do though).
She's also quite smart and appears to know stuff that a person of her age shouldn't, she has a weird way of speaking, that makes her even more great. In the EN ver. she often uses a poetical speech with a lot of alliterations (or at least that's how I "interpreted" it, since you know... EN is not my native language) and in the JP one she speaks like old japanese people used to.
But she's not only this, there's actually more of her, when the time requires, she turns into a rather serious and mysterious character (although always retaining a bit of her sarcasm) and you can't actually tell what's going on in her mind. She doesn't care about other's problems and other bullshit, she doesn't even care that she doesn't care.