"Chainsaw" implies that everything on the table is fully capable of leaving it to achieve the end product. Having a castable invincibility is also one of the reasons it is problematic to balance her atm.
And feelings aside, Kayle real problem is the lack of defined role. q: screams ap carry or hibrid, w: support or ap. e: hibrid or ad, R:support. Too many options are in the end too many bad options.