Master Yi is a very versatile AD champion that focuses around high AD burst early on and large sustained damage later. With the proper play-style, he is able to take out back-line carries/squishies almost instantly and immediately after deal massive damage to front-line tanks and bruisers. With this build, it allows him to do just that, while having enough health and mana to do his jobs without worry.

Like every champion in League of Legends, Master Yi has his own set of mechanics that when used properly maximize his damage, efficiency, kill potential, and survivability. Each ability has its own unique purpose and should be used to its full potential. Here's a rundown of each ability, and how to reach the maximum potential of each ability.
Double Strike (Passive): Every 4th consecutive basic attack, Master Yi strikes twice. The second attack uses an attack damage modifier of 50%, but applies on-hit effects fully and can critically strike. Double Strike's counter resets if Master Yi has not dealt or received damage in the last 4 seconds. (taken from league of legends wiki) This ability gives Yi one of the best siege potential in the game. He takes objectives twice as fast as the old Yi. Towers fall quickly, inhibs fall quickly, dragon falls quickly, and even baron falls to Master Yi's hands alone. Because the second strike applies on hit abilities and can critically strike, the build gives Yi 50% crit chance, 50% more damage with every crit, large amounts of attack speed so that the ability can be used as much as possible, and the sheen on hit effect. This gives the ability full potential damage output. When sieging towers, activating Youmuu's Ghostblade gives a large attack speed bonus allowing Double Strike to proc more. Other things will be explained at a later time when it will be easier to explain.
Alpha Strike (Q): ACTIVE Master Yi becomes untargetable and leaps to strike up to 4 enemies, dealing physical damage to each and dealing additional damage to minions and monsters. Each bounce will target the nearest enemy that has not yet been damaged. Master Yi re-appears at the initial target's location after the effect ends. Alpha Strike can critically strike, dealing additional physical damage equal to 60% AD. Basic attacks lower the cooldown of Alpha Strike by 1 second. (taken from league of legends wiki) Before going into how to use this ability to it's highest potential, I would like to explain what will probably be a controversial choice in my itemization. I chose The Bloodthirster over Blade of the Ruined King for 3 reasons, this counting for 2 of them. Alpha Strike has 100% AD scaling, and does not apply on hit effects. Therefore, a fully stacked Bloodthirster will do 75 more damage than a Blade of the Ruined King with this ability. This means that this ability will do more damage, especially when it crits for 60% more damage. The Bloodthirster naturally scales better with critical strikes because higher AD means a harder hitting crit. In this scenario, the Blade of the Ruined King just doesn't work as well as The Bloodthirster does. Now, onto how to use this to it's maximum potential. (coming soon!)