Champion Mechanic's ideas

So... i had this idea while watching you tube today, what if riot would make a champion that would be able to shape shift into champions on the enemy team? the only way i can explain how this would work at the moment would be to use shaco... he basically is the sneakiest champ in the game excluding Evelyn.. alright so basically this champion would obviously be a assassin, a sneaky character that when engaging would look like a team mate, so say the enemy vi is ganking your lane but instead it isn't vi it is your shape shiftier. this would be extremely fun to play not only its deceiving the enemy but also it makes the game style a lot more interesting as you wont know who is who. now i know this sounds strange because they will be able to tell if its fake by if their visible on the map but! the fact that you wont know for sure is the fun part imaging your jungler ganking but it isn't the jungler. the only way i think this would work is if the enemy would see them when they are shape shifted... which would add some counter play because if you see 2 vi's on the map then obviously one is fake... maybe there are other ways around this like maybe when he is disguised as a certain champion both him and the one hes mimicking are both unseen on the map so that way neither team can see them kinda like a mini nocturne ult around them

any way let me know your thoughts about this and if any one good with art could think of some sort of splash for this idea id love it, any way besides my bad grammar hope you like it