I've been playing League of Legends since Season 2, and I think I have a pretty decent grasp on things, however one thing has always perplexed me.
What does Yi do?
Every time I see Yi on my team or the enemy's, I'm always left wondering. What does he do? He doesn't seem to do damage, nor does he seem to provide utility or CC, so what is his purpose? Every champion does something, right? Help me out here.
He's a feast or famine team-sweeper.
dances really fast if he has ghost, ult and youmuu's
he's really fast so he's a good pick for when your team bans the champion you were hovering
What does yi do ?
He alpha strikes you early game, you flash into your turret and charm him to keep him there
Hes a mobile double buff delivery system
[sg-ahri-2]
Punishes teams that pick a bunch of squishies with low cc, especially ranged squishies who rely on skillshots.
A yi is never happier then when adcs get out of control and end up in 2+ lanes regularly.
What does Yi do? 
~~
Yi forces you to pick a point-and-click stun champion. That's what Yi does.
low cc yi will wreck your entire team
I cant tell if this thread is serious or not
Every time I see Yi on my team or the enemy's, I'm always left wondering. What does he do? He doesn't seem to do damage,
Do you actually know which champ is Yi or have you been assuming Aatrox is Yi?
What does Yi do?
Wins
Get blown up every fight because Yiis hard to play.
LSS:
Master Yi is basically an on-hit buildstick and relies on his Q and W for survival while his E and R just let him do more on-hits.
Yi-sets,,,,, that's what he does... or used to do back in season 3 with 100 percent reset on Q
TL;DR - Yi is a handicap champ, there, I said it.
Yi is an objectively shit champ with barely anything in his kit considering 3 out of 5 of his kits (including passive) are strictly AA steroids which are utterly useless unless Yi himself is fed and use the item and level advantage to steamroll with those 3 AA steroids, which it also begs the question about how he even get there especially against any team with coordination and/or have CC given that over half of his kit is dedicated to AA steroids. And this issue is also helped by the fact Yi has ZERO UTILITY, which makes trying to snowball early even harder.
Yi has his bread and butter Q and W and the refresh passive from R that saves him from being literally the worst champ in the game, and those stuff are pretty great. But then they also have high gatings with Q's earlier CD approaches 20 seconds (and 15 when maxed) which fortunately can be reduced by 1 second per AA but it's still pretty damn long practically by itself (note another focus on AA'ing, compound with the previous paragraph), however W ain't so lucky as it's on a fixed 35 second CD which is REALLY long for a normal spell CD, and lastly there is the refresh passive that you don't even have pre-6 and even post-6 you need to kill/assist to use the refresh passive which suggests you already need to be in some kind of lead hence begs the same question mentioned earlier.
Some time before someone mentioned that Yi will only ever be as good as how bad his opponents are, to much extent, they're right. As Yi, while you will not have much mechanical management beyond timing your Q and W efficiently and critically in hot situations (which is not easy especially in higher elos, but I'd be lying to say Yi has complex mechanical plays overall), but you as a player (assuming in any respectable elo bracket) generally have to be flat out better (as a 'player') than your opponent to play a successful Yi against them; Yi is completely useless, as a matter of fact if we just look at his kit itself as a package, Yi severely lacks the "leading power" to be able to direct the game as he wants but rather he can only react to enemies fucking up first as again his kit is totally useless (due to its AA focus and extreme gating on the remaining parts less to do with AA'ing) unless it's already fed for some reason (by capitalising the bad-ness of the enemy team). Hence "Yi will only ever be as good as how bad his opponents are". Well, I guess if you're so good, you can also just bait the opponents into fucking up for you to capitalise on as a Yi, which links to the other point, that you have to be flat out better than your opponent as a player in order to beat them as Yi.
See the point?
In short, like the premise I'd stated, Yi like a couple others on the roster, is literally is a handicap (again assuming in any respectable elo). Maybe not against total fucking noobs, but then again, they get rekt by anything just harder by Yi as he snowballs harder so it's not like it really makes a difference.
You might counter-argue "b-but, using your own logic, wouldn't that just mean every champ is a handicap?" Well, no, because as I've said, due to how his kit is, Yi can not "lead" the game but rather he can only "react" to it. And in order to "lead", Yi has to create a situation for which the opponents are baited or even forced into making mistakes for Yi to "react" to; it's indirect and certainly much harder to pull than leading the charge yourself because you're good at the game, as Yi often has to completely outplay own their opponents from head to toe and play them like a cat playing around with a rat to be doing the "leading". Point hammered.
Here do note, I am completely not considering the scenario of getting carried, because it's pointless to talk about for every champ.
But sadly, Yi is unlikely to ever receive his respect he deserves, as many people continue to ridicule and mock this already very bad champ and pretend that he casually 1 shots the enemy team for breakfast for memes or something, as people will just continue to meme this shit out of him (and his players) even tho the meme train about this guy died 3-4 fucking years ago already. It's very sad.
I guess he steamrolls your team while ahead? I've never seen him do good.
But he's not as bad as Wukong. Every time I'm against a Wukong, is a free win for me. I don't understand this champ.
he's a training version of singed. just hasn't learned how to be toxic to the enemy team yet.
he 1v5 the game. Top 5 scariest champs in the game.
His whole purpose is to one shot people apparently lol
His primary focus is jungling, he's got decent clears for jg camps, and some good ganks once you have a few levels. He's very much a binary champ though, either he does an amazing job, or he's absolutely worthless, and really good Yi's are not easy to find.
To punish you if you don't have the CC to stop him Fed Yi carries harder than anyone
He's an easy to use champion in solo Queue, requires little to no tam coordination or cooperation. He just needs to just show up to clean up and farm. When he has his items yi can pretty much 1 v 5 a wounded team. If a wounded team sounds too good for you it does happen quite often. All yi has to do is go in last. So his purpose is to clean up and then push.
I believe his main purpose is to fill a ban slot
He's a skirmisher, so mostly his job is to shred through enemies who try to get on top of the carries more or less. Honestly the Skirmisher roll is a bit iffy to begin with. They are sort of a sustain damage assassin, but have to be a bit with defensive tools better then most Divers making it impossible to 1v1 them, yet they tend to become extremely feast or famine. Yi on his own more or less reflects how a Skirmisher is supposed to work on paper, but without the escape tools that some of the other Skirmishers have (like 
or 
) .
Master Yi used to be a designated Melee carry until riot decided that ranged carries can reliably crit you multiple times before you can even get in their range
