Adaptive champion idea - be who you want to be

I think it'd be cool to have a league of legends character that is a formless cloud of energy that takes shape into a solid being as the game progresses. If it interacts with tanks, it gets tankier. If it interacts with marksman, it gains additional attack power and range. If it interacts with mages, it gains ability power and mana. If it interacts with jungle monsters, it gains additional damage toward jungle mobs and objectives.

It would have a very basic kit, but well rounded. A point and click slow, an auto attack amplifier, and a dash. It's ultimate would be that it can assume the form of any enemy champion for 45 seconds, accessing all of their abilities as they were when the ability was used, including their cooldown timers. This means if he assumes the form of someone on cooldown, he's useless and his ult was wasted. So you'd have to time your ult right to get the most bang for your buck.