.......It's really something, because I think you'll have alot of free reign to change Raki if you wanted too.
Raki is the complete antithesis of what it means to be a Claymore, the boy is just so darn human so much that the idea of him actually being a warrior is, well,
Why is he a warrior? Is his story the common tragic one? Was he sold out by his village the same way Teresa was by her parents(Good idea right there)? Is he interested in revenge? Does he fight for justice like Priscilla wanted too? Does he even care for what's left of his humanity and no longer have his benevolent personality?
It's curious; a situation like this I think is the only one where you could change him up if you wanted too. Of course, this goes farther into what techniques he will have, his rank etc etc.