I find this is the Ultimate Build for Mastery Yi! I had never problems with this build! It's just amazing! Speed+AD+Armor penetration is a really deadly combination! With this speed and strenght, you can attack the turrets ALONE (only at lvl 18 of course). I would prefer this build to all Master Yi and LoL Fans!

Everyone thinks: Why should i buy it? It's just low! or you don't need it. But i say to you: YOU NEED IT OF COURSE! And why? Because It's just amazing! It gives you AD,Crit Chance and a 5th Skill!! YES! This skill is just OP when you are attacking someone and have life steal! Or running away with the ulti!! It is helpful! Very helpful!

When you are at your tower with low life and an enemy wants to kill you and escape, just activate your W skill! Because you will get many armor and magic resistance while healing and the enemy champ will be killed from the turret :D

When you have Last Whisper the enemy tanks can go home!! Not even a tanky Olaf with many Armor can STOP YOU!

Later when you have tooo much money, you can sell your boots and buy a second phantom dancer! It's really good! Everything will be faster!

If the enemys got fed or when you have problems. Buy Warmogs or a good armor instead of Last Whisper =).... I would prefer the Thornmail because it gives damage to the enemys when they are attacking you ^^

Keeper of the ancient art of Wuju, Master Yi is a mystical warrior from the isle of Ionia. He descended from one of the few tribes dedicated to the preservation of Wuju, a martial art founded with the principles of absolute spiritual awareness of one's self and one's enemy. When the armies of Noxus invaded Ionia, Master Yi joined in the Ionian defense to fight the craven enemy, bringing his village honor through his unparalleled mastery of the blade. The ensuing battles ravaged the land, but no conflict inflicted as much horror as the day the armies of Noxus closed in on Yi's village. Left undefended, the village became the unfortunate test subject of the latest invention by an up-and-coming chemist, now known as Singed. The remains of the village that Master Yi returned to were so horrific that it remains a festering scar on Ionian history. To this day, no Ionian will ever publicly speak of what occurred.

After the Noxian invasion was contained, Master Yi fell into a deep isolation. For years, he trained morning to night, speaking to no one and refusing offers of consolation by fellow Ionians. The only thing stopping him from madly charging into Noxus battle lines headfirst was his pledge to keep the Wuju style alive. Even though he seethed with impatience, his rage became a tool for sharpening his practice of Wuju, developing stronger and deadlier skills for his eventual vengeance. The only thing that roused him was news of the League's formation, and Noxus' subsequent enrollment in the League. Master Yi now brings his mastery of the blade to the League of Legends with unflinching purpose: to avenge his kinfolk and end the predations of the Noxus once and for all.

''The art of Wuju lives on in Master Yi, and is plunged through the hearts of his foes.'' -- Soraka, the Starchild