Yup, play passive. Poke him, farm his creeps, but don't push to hard. If he doesn't get kills from you, often he'll get frustrated and go off to try and gank other lanes, letting you make some progress in yours. Wait for him to make a mistake.

after playing him a few times i've found his main counter to be swain just look at what his q targeted and place ur nethermore underneath the creep he'll be forced to either take the damage and return or b use mediate if he uses meditate u've essentially stopped him from farming for 30 seconds

Phantaztick, when I play ap yi, I dont get frustrated and leave, I PLAN to leave. Yi is very quick early game, and has the ability to farm up fast, leave to gank, and get back before turret is being hit hard.

Something you want to do with prolly ap yi AND kat, is FOLLOW them when they leave lane. Don't let your bot lane get out manned bcuz the enemy has a jungle AND a mid down there along with their bot lane.

Better yet play yi ap levels q w q w e, build zerkers greaves and 2 dorans before you start rushing zeals. ZIPPY!

if u played ap yi a bunch of times it's alot easier but generally the idea is to see where he alpha striked to and stun him when his alpha animation ends even if u can't kill him if u can chunk his hp he'll have to meditate and wait another 30 seconds before he tries it again otherwise u can just kill him the next time he does it. if ur teammate screwed up then just do the same thing but make sure none of ur teammates that have low enough hp to be 1 shotted by yi even if he in the far back stay otherwise he'll just shred ur team.

Also banishee veil doesn't help it actually helps him so don't bother getting one to "counter" him it'll block his alpha strike on u but it'll still bounce the other 4 times and damage ur teammates as well as not move him from his spot.

Could someone actually explain to me what the problem with ap Yi is? Everytime I've fought one or played with one, the ap Yi gets pwned all game. I don't understand it. People keep talking about him like he's gonna be some freaking diety that slaughters goats and eats people for breakfast...but then he just gets roflstomped harder than an Ashe that tries to solo lane against 2 opponents. What's so scary about ap Yi and why do I never see an ap Yi that can break a 0.20 kd ratio?

Just play TF against him and ruin his day with gold card. You might not be able to slow ulted yi but you can sure as hell stun him.

I play Cho'Gath against Yi mid. Cho'Gath has great range with his Q, the silence prevents Yi from using his heal, and Cho'Gath's passive grants him good sustain. Additionally, the true damage from R can save your life if Yi has low health and has just started using his W.

he meant "You counter AP Yi the same was as you counter Katarina"

I believe the issue isn't so much handling him in teamfights as it's people not wanting him to auto-win his lane. His laning phase is so obnoxiously strong there is virtually no way to win the lane on your own. Even lane bully champs require some skill/effort whereas AP Yi is just Q-Q-Q, meditate, Q-Q-Q, etc until you shut down the other mid and/or kill them for staying too long. Also, now that your highest damage hits turrets AP/AD, there is no drawback to going AP Yi because his AS steroids still make him obnoxiously OP at dunking turrets before you realize he's split pushing.