Champion Idea

I'm no wiz nor do I know how to create, write and or make a character but what about a champion who takes the form, shape and the ability power (statistics and abilities) like ditto from Pokemon except it's a person or like Mystique from X-Men.

Briefly she/he or it, takes control of an enemy champion or maybe cast on team mate? and the person (for sure they can't see enemy wards and or their map vision) can when in team fights be like an illusion or decoy, however it works idk.

Basically it's harder to team fight as you then have to be attentive to all the champions and etcs.

Lemme know what you think about this, it to me sounds really cool! :)