Keeper of the ancient art of Wuju, Master Yi is a mystical warrior from the isle of Ionia. His village was steeped in Wuju, and his kinfolk were some of the few to carry the tradition into the modern day. That is, until the armies of Noxus came to Ionia, ravaging the land. Master Yi went to fight the craven enemy, bringing his village honor through his unparalleled mastery of the blade. However, in his absence, the armies of Noxus closed in and tested the latest invention of the chemist now known as Singed. What was done to his village is something of which Master Yi will not speak. However, he has brought his mastery of the blade to the League of Legends in order to avenge his kinfolk and end the predations of the Noxus once and for all.Master Yi brings the art of the Wuju style in a way that makes his enemies falter. He is capable of fighting with lightning speed, as well as finding purchase behind the defenses of an enemy's armor. He can call on his inner fortitude, regenerating at an accelerated rate. Calling upon ancient forces, Master Yi can fold space, appearing behind enemy after enemy. He is even able to reject magic, rendering it useless against him.The art of Wuju lives on in Master Yi, and is plunged through the hearts of his foes.

Hey You!, yeah you, reading this guide. Before you play Master Yi. You will have to accept this oath. Put your right hand in the air, and agree to anything that's gonna need to be agreed to:

I, (Your Name) agrees that I will play Master Yi with not only my skill, but also with my soul. I agree to achieve victory with honor, and face defeat with grace. I am Beserk, I will Towerdive, backdoor the Nexus, and get my Penta-kills. No one can and no one will stop me. If I die, I will come back and roll your face. Twice. I will do the best for the interest for my competent team, and for myself.

Master Yi is not a Samurai, and neither am I. I will not be a coward and commit suicide over ONE feeder. TWO feeders… FIVE feeders. I will stand and fight against the 1000/0 Annie, or 9001/0 Olaf. I shall show that not only am I the only Highlander but Berserker. I will not surrender if I get ONE, TWO,… FOUR rage quits. I will stay till the end. I will never surrender and quit. I shall fight with my blade forged with the finest metal shining and gleaming with the sun decorated with blood of my enemies. I sit here in the battle field, waiting for you to surrender cowards, or I will wait here and face defeat?.

People say Chivalry is dead. Honor is gone. They are correct. But Wuju is not. As the upholder of Wuju and the leaders of the future of Humanity. I agree to never surrender, never give up!

Signed:
Lewtorz

We start here, "DEFENSE MASTERIES? U CRAZY BRO?"
I realize that most Master Yi's go offensive masteries because they want the "damage". But people need to understand that damage is useless if you're dead. You go defense masteries so:

A)Demacian Justice will 99% of the time never be able to finish you off.
Also you will survive being feasted too even though Feast is true damage, you get a 4% damage reduction due to your mastery.
B) Cleanse is going to save your butt so many times.
C)Dodging ftw especially for 1v1s.
D)You survive a little longer.
E)Nimbleness will help you run faster.

Runes are:
Quints are all Armor Penetration.(best dps late game)
Glyphs are all CoolDown reduction.(amazing early and late game)
Marks are are armor penetration.(best dps late game)
Seals are all dodge.(cause you need to live bro)

There a couple of items that are interchangeable here:

If they have 2 or more non-tank AP hero's you can trade ninja tabi for mercury treads.
IF they have 2 or more Full tank build hero's trade shurelya's for a Mandred's and build it before ghostblade.

This is an expensive build in order to pull it off you have to focus on creep farm until level 11-12 or until you finish atma's which ever come first, ofc if you see a winning battle jump in and ult before then and there is a 90% chance you will get the kill/gold.

when you farm with this build use alpha on creatures that are below 40-30% early game to assure the kill and you will prolly get other cleave kills with it too, alpha will harass the other team enough to stay back with little help from your own teammates. Don't auto attack in the creep lines stay back only go in with alpha you want to avoid unnecessary damage.

That is all the build is about getting massive amounts of gold.

!!!!!!BE-CAREFUL BEFORE YOU GET PHASE BECAUSE YOU ARE STILL YI AND YOU STILL GO SQUISH!!!!!!

After you get the full build though you will be able to jump into team fights and 1v2 situations and regardless the cc you will get a kill and get away.

!!!!!NEVER RELY ON A TEAMMATE TO SAVE YOU WITH THIS BUILD YOU ARE QUICK IN AND OUT IF YOU GET STUNNED CLEANS AND RUN UNLESS YOU CAN KILL THEM!!!!!!!

A nice trick with Yi is if someone is chasing you to your tower and trying to tower dive kill you just meditate it gives you a nice arm/mres buff to let you live and the other person won't realize it and get themselves killed this is also something nice to do if you are getting attacked and waiting for cd's to come up.

But that is all there is to YI tank good luck and have fun.

P.S. It's sorta like playing life steal yi but when you run away with this build you don't die.

SPECIAL THANKS TO... Jimmix's guide on league craft that lead me to this invincible style of play and most of this was copy pasta from his page with minor changes on my part to suite my style of play.