Start

At the start play normal Yi, and try harras with basic attack, sometimes Q and some attack, crit gives you more harras chance.

Early Build

Still play normally and try to hold as long as you can the Avarice Blade, really good amount of bonus gold.

Core Build

From now the AP style comeback for real: the Trinity bonus damage and the Infinity Edge crit to the Q and basic attack make your yi unstoppable if well used.
Engage activating R+Yomumu.
Watch out! the Q cooldown won't be deleted if kill a champ, but they will still 2 seconds left so try to hit at least once more after trinity to let your Q go out of cooldown.

Final Build

Have Fun.

This build meta is to kick *** in the old AP style but without making the Attack Speed, nothing, because if we build attack speed the build will become just like the other, OP and boring.
This build is for those people that want to use Master Yi without having to make an OP basic attack based build.
I hope you like this build and if you did put a Like :D