Now I'd first like to mention that this not my build in anyway. I came across it in a game and decided to share it here.

I used to play Master Yi before I hit the 30's and then I realised that in higher elo he is very tough to perform with. So since then, I lost intrest with Yi. But I have learned since my game with a Yi player that there is just so much about those 450 champions that we don't know. If you think about it, Ashe, Soraka, Kayle, Nunu & Willump and now Annie,everyone of those 450ip have actually a really high amount of potential. Ashe is considered the best AD carry, Soraka one of the best support, Annie the OP Ap, and Nunu & Willump has great jungling/ganking abilities.
I guess what I am trying to say is that we should never underestimate champions because of their price ( k except Sivir, such a sad story)
Okay let's get back to this Yi that was in my game who made me change my mind about Yi's potential...

P.S. : Well this guy gets his boots somewhere but I don't remember when so just don't assume he doesn't have boots becayse I didn't put them in the build.

So it's a game like any other, I go solo queue in a ranked game (my elo is about 1500ish). We have a decent team in general, Singed solo top, can't remenber who was mid, my Caitlynn was bot with a Zilean and of course we had this Yi who jungled. So he started at the small golems, his Alpha Strike didn't proc so I lost intrest and stopped watching him. Now I don't notice him again until he comes to gank bot till something like lvl 4, we manage to get a kill and I thought that this Master Yi ganked well but that's all.
Then he just kept getting kills, I mean at first I didn't think much of it, even if it is a Yi who is a tier 4 champion, you can still do good with it right?
Now he does something that catches everyon's eye. It was something like mid game (lvl 13-15 probably). The enemy Karthus was under his turret, with 80% of his HP and our Master Yi just ult and rushes in ALONE for the 1vs1. So we were like man cmon you were doing good, don't get cocky... And the enemy team was already Loling so hard. What happened is he cut down that Karthus down and survives because of Hexdrinker but he gets very low and Karthus didn't ult because he thought the tower was gonna get Yi. So our Yi uses Meditate to tank one extra hit from the tower and by then a minions wave comes in, he Alpha Strike the minions and gets health back because of Hextech Revolver and the extra proc damage from Alpha Strike on minions. He activates his ult again because he just killed Karthus and gets away.
Then during this game that Yi basically just carried us to the win...So during the game we chatted and he explained his build to me and here it is.

He starts just like any Master Yi jungle, with Cloth Armor and 5 Health Potion. Then he goes to Wriggle's Lantern. He also get Hexdrinker because it allows him to kill AP way easier, as in that fight with Karthus. Finally he says he gets Hextech Revolveror Catalyst the Protector for more survivability and sustainbility in the jungle.
Of course he gets boots somewhere but I only asked the reasons for the first items, I mean from there he builds like any typical AD Master Yi.

So what distinguishes his build from the other builds is really just three items : Hexdrinker, Hextech Revolver, and Catalyst the Protector.

- Hexdrinker gives you a good deal of Attack Damage for better damage in general. Some Magic Resist. But the MOST important is really that 300HP shield. Now agreed that the shield is rarely useful lategame, but EARLY game it grant a GREAT deal of survivability and chances of getting a kill.

- Hextech Revolver this gives a great heal for Master Yi when you proc minions etc... This saves you from many trips back to base, I mean you can just walk up a lane Alpha Strike some creep and get back to doing your thing. It is just like Hexdrinker, it gives you a hidden card in fights : hey he's low--->shield, now he's gonna die---> Alpha Strike those minions near you.

- Catalyst the Protector is another item he said he uses sometimes for the health/mana and regen every lvl. It basically again allows you to stay in the jungle longer and gives you some survivability in fights. And then you can turn that into a Banshee's Veil for their AP.

Now of course I had to try this build b4 posting it here. And what I found is that this build allows Master Yi to be somewhat more tanky in the early-mid game. That in return allows him to die less and farm better. And that is something that Master Yi really lacks, because if you as Yi die by ganks while jungling or something else, it will really does affect your ability to be a threat late-game. Why? Because Master Yi IS a AD CARRY and needs those AD Item as soon as possible to do something in the game.

Well I hope that this build has intrested some old Master Yi players like me, and that they will be curious enough to try it and ty for reading this.