Well I just joined Mobafire and this is my First build. I tried it out in numerous custom games and found that it works well. Critting all the time with over 300 Attack Damage is rather fun to watch :D Anyways, I play Yi at Top lane. I never really liked Jungling.(Sorry Udyr) I start out with a Doran's Blade, with your masteries, this should give you 6% Life steal. For boots I get Berserker's Greaves, These are easy to get as they are only 920 Gold. So enough minion kills should provide the gold needed. If you Have extra gold you can buy a Long Sword after your boots. I Build the Long Sword into a Phage, which then turns into a Frozen Mallet. The Frozen Mallet provides some health for Survivability and Slows your enemies to make sure they don't get away from your.....Blood-Stained blade. Next is 2 Phantom Dancers. This helps you in the Crit chance and Attack speed Department mostly. Optionally, you can Get rid of Berserker's Greaves and buy an Additional Phantom Dancer for 125% Crit chance after you buy your Infinity Edge. The Infinity Edge gives you a nice Boost to your Attack Damage and Crit Chance, So make it a Priority. Yi can easily be countered by Stuns and Knock-ups so that's when Exhaust and Flash come in. Well thanks for taking the time to Look at my build, Hope you like it! And again, This is my first one :| Oh and one more thing, Wuju Style gives you somewhere around 310 Attack damage instead of 265 :D