Master Yi Build
Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
The Black Cleaver - If you are facing realy tough tankers or heavy armored teams, this will rip them apart.
Guardian Angel - Imho the best pick for ranked games as last (6th) item.
In VERY VERY late game you can swap boots for:
Banshee's Veil - For heavy caster teams.
Last Whisper - Item for lategame armor penetration for ppl that face heavy tanky teams. Get this only if you already got Infinity Edge.
Force of Nature - for Heavy AoE teams (Fiddlesticks + Karthus combos for example).