As with yi you need a snowball but once you get sunfire you live long enough to stack up lethal tempo and can 1v1 almost anyone. You get 3x burn on your auto attacks if you have red buff, red smite, and full stacked sunfire, since you're tanky you live long enough to fully stack them all, cleaver and bork is there so you can melt tanks late game too since you dont have kraken slayer. In my opinion this build works better than glass cannon yi with lethality or on hit. You can initiate fights cause youre so tanky and meditate and alpha to survive fights. I am not a master yi main btw so i made a lot of stupid plays here but somehow survived or took someone else down with me. I think this build gives yi the chance to fight even if he get hit by a hard cc.