Just done reading the last patch. And Yuumi got nerfed again. Since release it was one of my favourite champions, and until last patch is still was. Despite not having such a high win rate in lower elos but only in professional play, it got nerfed every single patch since release. First shield reduction, then removal of mana regen from passive. Then countless nerfs on the Q, over and over. This last one is definitely ridiculous though. 20% for 1 second slow makes the utility of yuumi in helping the adc secure the kills and her engaging power drop way too much. Already in soloq it's hard to coordinate with other people, as they often will walk you out of Q range or ignore the pings and just loiter around.
Now the window to make the adc understand you're engaging is even smaller, the enemy will have plenty of chances to run, and also Yuumi loses one of the few skills that could help her escape in case the adc died. 20% slow on a champion with her ridiculously low hp and defense means that she'll have no chance use the slow gotten by landing a (straight) Q on an enemy to escape to the safety of tower or a different teammate. 20% slow won't be enough to go anywhere, especially for those that like me play her without boots as boots on yuumi are a wasted slot if you keep your team alive.
So I have some great suggestions. Let's also remove damage from Q completely, the heals from her E, and the root from the ultimate. Oh, and let's make it a 5 minutes cooldown on W to be able to attach to someone else after someone dies. That way it'll be the perfectly useless champion everyone seems to want. Like, seriously. If she gets nerfed some more the ADCs complaining about an "afk" support in champion selection will start being right. I feel this update is pretty much the one needed to make it so.