I have played master Yi as my main since level 1 playing and perfecting my build until i could beat anyone. This build is built for going mid as master Yi, now I always laugh at the players who commonly say "yi is terrible mid" or "ur a noob mid yi really?" then I have the final laugh when i go 9-1-1 on average. This build revolves around massive attack speed and life steal

I rune for armor pen because it is essential for early laning in mid against such characters as vlad,cait, and urgot...If done right yi should have 25 armor pen at start meaning the enemy champion will have negitive armor which in yi's case is a HUGE advantage. The dodge chance runes are just for basic survivability in mid and the cooldown reduction helps with early harrass.

Now I have a basic AD mastery for Yi but the key is the extra armor pen and neutral monster buffs which great when you hit mid game

I always start with the boots lvl 1 when going mid it greatly help you dodging skill shots keeping you in mid longer then finish greaves for the same buff and alittle AS. Now you build emblem of valor which if you play correctly should insure your ability to stay in mid with a decent regen and great lifesteal. Go ahead and finish starks which in 90% of yi's builds is a key item. Now that you have a decent AS/LS we start to build one of yi's most notorious features...his move speed, build into zeal and then into phantom dancer giving him a 429 movespeed and even better AS with some bonus crit. At this point yi is pretty solid with AS/AD/LS/MS but his damadge is still not great and his crit chance could be higher leading into the best choice item Infinity Edge once this item is built it is GG for the other team Yi can not be stopped the damadge and crit chance matched with his previous items ensure a swift death to most champions. At this point the enemy knows yi is a major threat and will 9 times out of 10 build thornmail aka Yi's bane which to overcome I build massive lifesteal which leads into bloodthirster not only for the lifesteal but the major damadge that comes with it. My final item is Youmuu's ghostblade for even more armor pen and AS to finish off champions and any tower killing needs.

Always take alpha stike level 1 it is the best way to harass at early levels providing decent damadge and closer for a good auto attack or two. Wuju is also key because our build relys on AS and LS so the damadge buff is needed. Now take yi's ult and max out alpha strike and wuju style and finish with meditation. Now here is why you dont take meditate until the end game...In mid most people say meditate but really the heal vrs the mana cost is not good enough quickly draining you of mana and leaving you with no way to close in to your enemy plus most of your healing is coming from your items so it should compensate for this

My favorite combo for mid I cant tell you how many times a fight has arrived where i closed in and get exausted and they go for kill and i cleanse exaust combo them leaving them baffeled and giving yi another kill it is VERY satisfying

Now i will go into how to play yi in mid...As you start your first minion wave hide behind your minions and take out minions until only 3 are left at this point alpha strike to the enemy champion and auto attack him. you just did 100-150 in alpha strike and another 100-200 in auto attack if you cant exaust for the kill yet wait till next minion wave and repeat this process till you can. Now while in mid your survival from skill shots is based off your constant moving dont EVER hold still in mid hit and run keeping the enemy on their toes. Once you built into emblem of valor your life steal and regen should keep you in mid until mid game...at this point if your doing well have a few kills or the tower if your lucky. Now after starks you should be free to grab a red or blue buff and start going top or bot for ganking champions. Ganking is very easy for yi ping a target whom you've decided to kill and pop your ult and alpha strike to him at this point the target is running scared chase him down and get the kill exaust if nescessary. repeat this until team fights insume. team fighting with yi is perhaps the most fun part of this build. Never initiate as if you get heavy cc your dead so wait till teamfight is well engaged and alpha strike in from the bushes or from the back of your team and KILL THE SQUISHIES! and watch the rest of their team run in fear as you make quick work of the surviving members of thier team. When not engaging in a team fight or out of reach of one always back door towers master yi is great for this and will draw the enemy team away from your comrades and let them do work. Alot of this build is practice that needs work but if you pull it off well you should dominate the field GL HF and leave comments with suggestions or queastions

PROS
-with yi's lifesteal he can solo all champions
-Mid yi feeds alot more leading to a strong carry mid game leaving ganks for him
-if done correctly you cannot be out harassed
-laugh at non believers when you go 3-0 by 10 minutes

Cons
-if you run out of mana your farming and harass are done
-you cant start teamfights but only finish them
-this build works best in mid and may lack in others where 2v2 has more cc

Id thought id dedicate this chapter to a cool early harass trick that 9 out of 10 times gains me a kill. When miding get to your double strike and wait till there is only 3 minion and alpha strike to the enemy champion and hit him once this always drops them to half if you cant finish them there pull off and wait till u can again i've calcualted this move does about 400-500 damadge early game so perfect this technique

When farming dont alpha strike the melee minion just auto attack until only mages are left the aplha them getting a good hit on enemy champion as well great early game