Kayle is probably the only champion that can fill ANY role fairly well. She is most popular mid though, but see her less after the q nerf. CAN be AD carry, definitely scales well enough into late game, can certainly go top as she hardcounters half the common top picks, has...supportive spells but cant exactly do damage if she doesn't farm. Also an excellent jungler, moves around so fast, can dive really hard with her ult, her passive also really helps whoever she's ganking for; whoevers getting ganked is going to lose half their armor and MR early game during her slow, allowing the laner to rip them apart.