Yuumi gameplay
To be honest, the new champion doesn't seem bad at all on both playing or against. She doesn't seem overloaded so that's a start. However, i think her R's speed needs to be toned down a bit because it looks too fast to step away and too instant.
This champion is probably specifically designed to stick to an ally, so a solo lane will probably be a very bad idea due to the Q. I think Yuumi is a well designed champion really. Will be looking forward to play her.