Alright, so I'm writing a fantasy story, and I have two characters, Aiden and Riza. Both are trained by Arngrim, the wise old master, though he mostly deals with Aiden, because Riza is a girl, and Arngrim is reminded of his daughter by her. Effectively, the two of them serve as the party's fighter and magic user. The way magic works though, the Aiden can use it, if only in a roundabout way that requires things I don't really need to into at the moment, do I? Well, what I want to happen-- what I want to do is have Aiden break his leg, or otherwise be rendered incapable of properly using a sword in battle, and to have Riza take over and force Arngrim to properly train her so that she can protect Aiden, instead of the other way around. And I plan on having her turn out to be a natural at it. What are some suggestions for something like this, and I guess I'd kind of like to know if a switch of roles has been done, or --since I don't doubt it's been done, what hasn't?--what some other examples of it have been.