Hello guys this is my first guide and it is on MASTER YI.
I think this champion is a bit under-rated or miss-used and i would like to give my personal opinion on how i think he should be played/built and more importantly LOVED xD
The second build is kind of troll since you don't play in team fights but you will be a hellish doorman to the other team since they can't deal with you. (kinda like singed but you push way faster)

Pros
-Tanky Dps
-Resets
-Sticks to target
-Wears goggles
-Faster than a roadrunner since he can't be slowed
by neither movement or attack speed reduction (****s Nasus)

Cons
-Gets destroyed by Hard CC
-Falls off at Mid Game
-Hard Focused in Fights
-You will get criticized for playing a "noob" champ that goes 20/0/0

So now that i have your curiosity i will need your attention, runes are the thing that make yi a huge monster in the early game. Get Flat Physical damage marks and quintessences and then at lvl 1 or lvl 2, get your passive on, alpha the enemy and let the magic happen, he will be half health xD
This is the secret art of Wuju that i learned while playing yi and i promise it usually strikes fear in your enemy allowing you to zone him or get first blood if he is idiot ^^

I use basic mastery but i like to take the dangerous game mastery so that you don't get out of mana when you get your reset (very annoying). Then again the physical damage is needed for the early game and the rest helps you for your late game since you will be a tanky dps.

The skill sequence really depends on how the match up turns out, you may get another point in meditate if you use it a lot but 95% of the time i go for this skillset.

In a Team Fight you have 2 choices:
-if your AD is fed try to peel to him (protect him) and also deal as much damage as you can since yi does a crazy amount of damage.
-if one of their carry is fed you should just go or him but not immediately, be patient since this is the key to wuju and jump when he doesn't expect it. Alpha strike makes you invisible for a moment and this leaves a slight window to take out the enemy without him noticing you were attacking. Then since you are tanky and reset is coming just hit what you can and let the magic happen.
Don't forget that master yi is a very good split pusher but since my team usually can't stall i try to stay close but if you are behind or you have a strong team that can hold 4v5 don't hesitate and split push it will make you very strong.

First, i talked about it in the rune section but this is how you get First Blood at lvl 2, just hit the minions till you get double strike and then jump on enemy and destroy him.(RUNES ARE NECESSARY TO PERFORM THIS TRICK)
https://www.youtube.com/watch?v=HIaYpTHYkjo
Here is a video of how you do it (look at begining or the full game if interested ^^ )

Then you should also try to keep your alpha for when people flash to jump with them, it seems hard at beginning but you will find out that flash timing are actually easy to get and when you master this no one will ever escape you.

Finally dont hesitate to stack double strike, jump on enemy and get out since you will in most cases come out on top.

So for my second build, you will just play for turrets hence naturally taking Teleport.
Since you are master Yi, you can 1v1 almost anyone and when you get sword of the divine enemy team will need at least 3 people to get you which means you team is 4v2.

Try to to ward and put as much pressure as you can on the map, you may die but with ult+youmu you should get out of any situation. This build works in the jungle and you may take wriggle's lantern to get the fastest clear time of the game.

Thanks for reading this guide, don't forget to leave a comment and vote for feedback and more importantly don't forget that
"In me Wuju lives on" Master Yi
Don't Forget to check out my Master Yi Yionian skin with nice particles at:
http://leaguecraft.com/skins/38003-master-yionia-with-pink-particles.xhtml