First, I would like to say that this is the build that I had the most fun organizing and posting on this site. I will not say that I am an expert on League of Legends, but there several games with Master Yi. I have found something that works. I try to stick with a formula that I know will have a positive outcome in some degree. If there are any problems with this build, let me know, and I will learn from it.
I think this build can be very viable. It can also be shut down hard. It is primary based on the fact that your team picks champions that will help you out in some small way. The best way to support this build would be to have a nice bruiser that is able to take some of the damage. That being said your role would be that of the assassin. I would say this exactly. Pop in with your "Q", hit your "E", release your active items, and then if the team is still standing take out the weak ones with your "R" and exhaust. The most important thing to remember is you have a barrier. This barrier can save your life. In a game versus Darius. I had a Kalye on my team that shielded me from the dunk. After that the barrier helped to shield me from any remaining damage and take a triple kill. Be warned that this build have also cause you to "Kill steal" a lot. The one unfortunate thing about this Master Yi is the amount of damage that you can send out. It can be staggering. I hope that you take this to heart and try it out.
This build is a very hard one to play. You will spend a lot of time managing the items that are not on cool down, and the abilities that are also not on cool down. I prefer this Yi to an AP Yi anytime. He doesn't have a terrible meta fall off. The other Master Yi's that I have noticed that go AP have great success early game; however, fall of late game because they have no sustain or just they can't put out enough damage with their "E" and "R" that are scaled of attack damage.