[@KoL] I think Nanoha has the advantage in sheer size of lasers and scenery damage, and she's personally tankier than Medea is (but a lot of that's the barrier jacket, so in magical protections they're even), but in actual threat? If Nanoha landed something square on Medea, she'd probably get a funny look. The other way around, things would go [i]very[/i] badly. Pretty certain the only Nanoha character that would have a fair chance in Fate like that is Reinforce. 

Kind of the curse of being a magical girl and needing to be nonlethal. Plus the fact that Medea can outright suck in magical energy you try and hit her with. xD