i noticed that teemos shrooms bouncing off of each other is pretty useless : )
it wouldnt be if you could throw them in quick succession, without having to wait for one to land and having them explode upon hitting a target, without waiting, like ziggs bombs. they dont fly fast enough to be op, there is plenty time to dodge, but his ult wouldnt be useless anymore, and could actually be used in fights even. but most importantly...he would be fun again.
to avoid the stupid people commenting: you can always turn the damage or their travelling speed down to make em "less op", which they clearly wouldnt be anyways. this is not about making a champ op, but viable