Master Yi Build
Not Updated For Current Season
To start, this build is NOT meant for anything but a heavy tank team. You may use other runes than the ones specified, but these are the ones I use.
Yi is a quick-footed, fast-slashing, killing machine.........Unless you find yourself against a tanky team. And assuming they're tanky, and you have great confidence in your abilities, they will no doubt buy thorn mail, and as much armor as possible if you start getting fed. I have been Yi in a game against a Rammus, Shen, Galio, Garen (Pre-Sunfire nerf) and Amumu. All of them had revive and fortify.
Now you may be thinking "Just a troll team" but you're absolutely wrong. This team can mess up ANY team early and mid game, and if they are good enough, they can finish it before your team has the chance to start getting strong. This does not apply to just these champions, it applies to any tank. This build is meant ONLY to combat a mostly tank, if not all tank team, which we all see now and then. This build can be change up a bit if you do not find the enemy team too tanky.
I assume that if you're using this build, you already know your moves, so I won't bother going over them in great detail but...I'll explain why you should max this or that fast.
To put this loosely, all items are based on the situation of the team. Right now, you may be saying "There's not much in the way of attack speed...." Then change it! All builds are suggestions! You edit it the way you feel is best! Now, on to the items guide.
If by end game, they have not yet realized how stupidly strong you are, then don't bother getting any armor penetration, as obviously, there's no point. If that's the case, either go with a little more crit, or some more life steal. Either can make you deadlier than you already are.
If they were smart, and saw that you have been wrecking everything in sight, they'll all have lots of armor, in which case, you may want to skip out on the Infinity Edge, and instead get a Last Whisper. I know this will Sacrifice a LOT of crit, but you will hit the tanks like they are all playing Twitch.
Berserker greaves are what you always want to take. There is no point to Merc Treads as you already have a cleanse.
For all Yi builds, laning or not, there is something you can have fun with, that has no real downside on you at all as Yi.
Alpha Strike-Ever want to harass with Alpha Strike, but you're too afraid to because you might be killed? This here is a trick that works to do just that! Look for the closest minion and stand as far back as you can. Obviously, your minions will kill enemy minions, and if you see a minion with very little health, if you can time it right, you can Alpha Strike the minion, and during the .5 seconds that you are rushing around in Alpha Strike, if the minion dies, you will not go to where his body is, instead, you will reset to where you originally stood. This can be very useful for less dangerous harassing. You need to be sure though, that you can do this! If you can't, and you think you might die if you mess it up, don't do it! If you know you won't die, do it, you might bounce off and hit both champions, and reset to where you were standing, far out of dangers way.
To start, grab your cloth armor, and potions right away (The potion amounts are all your decision.) Put your point into Alpha Strike (Proc to deal extra damage to minions). After you've done that, head to Wolves or Golems, either works great, unless you have confidence in your abilities, and possibly luck, to be able to kill blue or red buff. Whenever you start off on a group of monsters, you want to open with Alpha Strike, and hope that you proc your ability with it. That will hopefully speed up your jungling, and decreasing your time until you get to 6. Anyway, once you are done killing Golems or Wolves, move to the one you didn't kill, and of course, kill them. You can use your smite whenever you please, I usually use it on the first group, and skip it for the second. After you kill those, you will want to go to ghouls, make sure you have been using health pots if you are below 3/4 health, to keep at max. Before you engage, ask your mid to move as far away from the corner as possible to keep them from sapping your experience. Once they have done this, Alpha Strike. As you know, you might get your proc, and if you're really lucky, you'll clear the whole wave, no problem. If you don't, and they all are low health, just kill them normally, if they aren't low at all, smite the big ghoul, and fight as normal. After this you should have roughly enough for a Madred's Razor (If you don't, continue to jungle on small creep, unless you have confidence to kill red or blue buff, if you haven't already) If you do have enough, go back, buy the item, and hurry to the closest buff, red or blue, and get started. Alpha Strike, Wuju Style, and Smite, rinse and repeat until dead. Once you've cleared both your blue and red buff, you should be level 4-5, if you are 4, level up at least once more through jungle creep. When you are level 5, look at the lanes. Is there a turret being pushed? Are people pushed out very far on the opposite team? If either are happening, rush to the lane ASAP. If not head over to the enemy blue buff and kill it. After you've done this, you should be 6, and should be ready to gank.
By this time, you should be level 6, have your ultimate, and still have your red buff. Try and get your boots before deciding to gank. After you do that, shis is when you'll want to gank a lane. The choice is all about who's pushed out, and who's not. Remember, your red slows on hit. Also decision is based on who has lower health. You definitely do not want to go after a Rammus at full health who's slightly further out than a Mundo who's back a bit further with 1/2 health. ALWAYS MAKE SURE YOUR TEAMMATES KNOW YOUR TARGET, AND THAT YOU ARE GOING TO INITIATE SHORTLY After you've cleared that up, get ready to Alpha Strike in, and slice and dice yourself some gold. Alpha Strike in, use your Wuju Style, pop your ultimate, and go as fast as you can for the person you're targeting. If you happen to kill the person, and the other person was dumb enough to stay and fight, guess what? If you got the killing blow, your ultimate and Wuju Style are back up. Pop your ultimate again, but do NOT pop your Wuju Style a second time. By doing so you'll get what they call "Double Wuju", where the passive and active are stacking. This will incredibly increase your attack damage for a short period of time. If you score a double kill, excellent, head back to base, buy some items, and head into the jungle. Their jungle, or your jungle, whichever one has more creep up. Gank when you can, and make sure you gauge the situation before you decide to dive in. Dying is only going to make the enemy team even more beefy than they already are. That's why you have cleanse. Make sure to use it when you need it.
By this time, (hopefully) you've been ganking as much as possible, and have many kills. By this time, I imagine almost all the people on the opposing team will no doubt have a lot of armor, and a thorn mail. This is when you'll want to have armor penetration. If you've stacked enough of it, it won't even matter that they have armor, as you'll tear through them like paper. At this point in the game, they WILL focus you. Meaning...let your tank initiate, and let everyone else get started on the fight. Once the chaos has been going for a little bit (And by little, I mean just long enough for people to get tunnel vision) you'll want to jump in and start killing. Ult, Wuju, Alpha, and go go go go go! Target the lowest health on their team, and burn through him, and move to the next target. If there is a Rammus, he will have been stupid and ball curled before you even join the fight, meaning you should save him until it's down. You do not want to hit him while he has this up, as you will hurt yourself, more than you'll hurt him. Hopefully, you'll be fed enough to the point where them being tanks was a stupid decision. Rally your team, this isn't just for this build, you ALWAYS want to make it clear who you're going to focus long before any battle starts. You do not want to run in without a focus, and end up dying.
This is a work in progress. I'll be updating it later, the build is still here and set up, but I'll be adding more. Question, comments, and suggestions are appreciated :)