Originally Posted by Demando
you explained it well, it does sound a bit OP but if it was just for a few sec's it won't be that powerfull (lets say like 5 secs pr something)
Even if it was a matter of 3 seconds (Which is hardly time to do anything) any and all AoE's that champions allies were casting are now buffeting him painfully (which may be fine for when the effect ends) but you still turned it into a 4 v 5 with one simple spell, and being able to choose any foe (including their strongest most fed members) means that it can easily devastate a team by taking away their most valuable members. Not to mention you can use a long cool-down ultimate on his own allies, crippling his champion and also crippling the former allies he uses it on.
Why don't you just make an ability that allows a champion to be effected by his teammates attacks for a limited time? It wouldn't be puppet-master, but it'd give benefits of any AoE teams shutting down their allies, any stray shots hurting their allies, and so on.
Or, if you're set on this mind control idea, why not temporarily make them like a pet, instead of taking them over, and give it a channel time? That way, if you control a foe, they can stun you and free their ally, and still give you a few seconds to attack his friends and take hits from his former allies (temporarily).
P.S. I'm not saying its a horrible idea, it would just be hard to implement into the real game if it ever were, it instantly, even temporarily, turns a game into a 4 v 5 the way you have it now, and a 4 v 5 (especially when you're taking over one of their strongest members) can immediately
cripple a team.