I think yuumi is being severely underestimated.

And admittedly i underestimated her myself. even now i think she has more hidden power than what im seeing but my opinion of her has changed. played correctly she is VERY hard to kill if not impossible with a competent team/host that is actually aware you are attached to them making her a great user of . Her W also allows for some neat tricks such as blocking skill shots then jumping back to host and heal up in safety. Her W is the MAIN reason why this champion is better than what the pure numbers show.

As long as her host is alive she can heal, deal damage, and CC at ZERO risk to herself. The only risk she takes is when she dismounts for 1 second to gain the shield but she can hop right back on host once shield is gained for a permanent shield to host. this is a pretty big deal because any other support has the risk of being targeted down by an assassin and taken out before they can really do anything. Yuumi can just spam heals, pokes, and CC all day and keep carry alive all day. She works best with mobility champs like etc. Champs that can already keep themselves alive and handle themselves while also keeping you alive as you heal and shield them aswell as giving them a huge amount of passive AF.

And the AF they get is a pretty big chunk. late game with a maxed out W its something like 130+ AF which translates to 80 AD for AD champs and 134 AP for AP champs(this is all based on the amount of AP yuumi has). this is why and are pretty important items for her. Thats an entire item worth of pure stats and its what people DO NOT see or notice. giving a or 80 extra AD of stats? FOR FREE? who wouldnt want that? Like i said, this champions power is very hidden just because of her parasitic nature which is standard for the course of champs like her. Abathur is exactly he same way in HoTS, no one ever notices the power he brings to a game but people still acknowledge he is a very strong hero in that game (or atleast he was when i played, have no idea how he is now)

Her heals have that same hidden power because people are for some reason looking at the lower number and forgetting that it has 2 charges meaning you can heal twice at once. and the charges recharge pretty quickly. but what really makes her heal insane is which can be charged to its maximum from 1 max ranged Q. and since she has 2 charges on her heal you can basically get to max charge with Q, E to heal out charges, Q to get max charge again, heal out max charges, Q again to get max charges, and while your E is on CD you jump off to AA for shield, hop back on host, and heal out the charges again. so ya is a mandatory first buy item. takes alot of mechanics to pull it off, but the healing is INSANE. on average i can get 25k-50k healing depending on how long the game goes on.

With all this being said im not sure anymore if she needs buffs right away. maybe a CD reduction on Q? as i said before alot of her power is very hidden. im not claming to be best yuumi, main yuumi, or even a good yuumi. Im simply giving out my opinion and observation based on my games with her and games i see her in.

oh and FYI, stop taking on yuumi, its actually useless. also FYI, she is not a sona clone. she plays NOTHING like sona. even her ult, which everyone is comparing to sona ult, plays alot differently because of her W and the fact that she can move while ulting.