Hey,
Master yi is a little squichy early game but when he gets his build he is really powerfull. The dorans ring is awsome start item cause it gives him a great stay in lane power what makes is farm easly.
With this yi you just have to play a little defensvli on the begining and try to farm the max you can. Once you get midgame try to get in teamfight after they spent their cc skills or you will be easly taken down.
Once you get life items you can go for their squichys easly and take them fast. Since is CDs refresh whenerver he kills with ulty u can take the entire team if u got it right and focus well.

Try it plz and dont vote down before doing it till the end. Hf and harrass them =D
Sry for my English