Volibear + Kog'maw Toggle?

What if Volibear's ult was some kind of toggle? So while it was on, it costs idk... 20 mana or something per hit or per second. Or maybe even switch his passive and his ult so lightning always bounces around and he can ult to heal himself and grant bonus AD (maybe it's too similar to Mundo...)

And for Kog'maw, I think his W should either: Be longer duration OR Have a shorter cooldown OR have some kind of toggle effect And maybe his Q and R should have a bigger ap scaling since people play him AP, but his Q sucks cause it is hard to land