I just had a pretty tough game with a Yuumi support. I don't want to be negative Nancy but there's a huge issue with this champ. I love the idea, love the cartoony characters and cartoony magic. I actually like Yuumi's kit but it's just broken.
I can't speak for all players but when Yuumi literally stays attached to an ally all game it's no different than being AFK. Yuumi can attach, and do nothing at all. Then when you say something all they have to do is say "saving mana" and "part of her kit".
I'm going to start reporting Yuumi players for going AFK if I get suspicious and I feel like Riot needs to do something to keep an eye on these Yuumi players to make sure it is "using her kit" and not just spectating the game.
Yuumi is able to attach and detatch herself.. so unless I see her hopping on and off the ally it's AFK gameplay. It's just incredibly lazy and when your team is suffering because you're literally turning a 5v5 into a 4v5 then it's a problem.
I think her kit needs tuning. Make the "W" a channel ability with a Mana per Second cost or something to make it costly in order to stay invulnerable.
It's a slap to the face tbh when every other similar mechanic only lasts up to 3 seconds on a high cooldown. Or make her spells cost more if she's using "W". SOMETHING to deter floating around doing nothing.
Fizz, Vlad, Bard, Trynd, Kayle, Taric and Watch/Hourglass... becoming "invulnerable" in any way is something calculated, and once it's gone it's gone.
Yuumi is literally Vlad stuck in pool form being able to cast his other abilities. ??? That's balanced?
Invulnerability should be something you have to pay for, and shouldn't be a quick access mechanic.