Ill go into a lil more detail about why being effective is better in the early game.

Yi is a great champ, but he is just to squishy. If he gets focused by heavy hitters, he goes down fast. So in the early game he needs to be aggressive, but has to take caution. With the build you have, you should start building Warmonger's asap. Since HP is the core of the build, you want those items first.

Personally, since you are running ArP, I would suggest getting a long sword to start, some HP pots, and open with Wuju Style. This will give you amazing dmg to start the game. This will lead to faster farming, and you wont be harassed as much, due to the fact that what ever champ you are laning against wont have minions to hide behind. I would suggest getting Brutalizer too. This gives him great power, and stacks with your ArP. If you have that great dmg early game, farming and killing champs will be a bit easier. Yi is soft so you have to make the best of his dmg output. I would also suggest, having 3 ranks of Wuju Style before lvl 6. Again, its the dmg early game that makes Yi better in the late game. Once you build Brutalizer, start making Warmonger's or Frozen Mallet. Than Atma's, and last Bloodthirsier. From there you can get what you want.

Yi is a late game champ, and is item dependant, so starting with items that with your rune and mastery build, is the best thing to do. Heres an idea. Just so you can see the effects of your posted build, and the effects of what I suggested, go to EDIT BUILD, and make another Yi. Only make the one with the suggestions I gave. Than compare and contrast them.

Hope this helps

why thank you for your constructive critisim. i appreciate it and will take all of what you said into consideration. i am still pretty new to LoL so i dont know too much about all the proper strategies as to how to get it going. i can see what your saying about not very effective to start with what i do. but i find that in the end it is very much so worth it. i dont necessarily buy these items based on how they look but how they seem to combine with the high dmg with LS and attack rate with damage, i never really knew what i should use to gain health so i just thought that the high health regen and the slowing effect that warmogs armor and the frozen mallet combined with the high movement speed and attack rate it would do fantastic because i find that when lvl 18 i can go and completely heal my self as well as get the kill rather fast. but thanks again for teh advice i will definitely try what you suggested

This costs 13,660 gold. Thats not bad cost wise.

Dont start with Vamp Scepter. This is a common thing that ppl think is great, but its not. Yi doesnt do enough dmg early game to make LS effective. You are running ArP runes so props to that. But if you are gonna have dodge seals and PD get ninja tabi for boots. Greaves are ok, but if you are running into a melee based team, and you got dodge, build on that. Malady is a subjective item. Some ppl like it, which it is, but you dont have enough dmg early game to get this early. It just wont be effective.

If you play WoW.... Malady=lvl 10 Rogue with 2 daggers.

You wont do hardly any dmg, and therefore LS wont return as much.

Another thing, you have crit dmg runes, but you arent doing anything to help them help you. PD isnt gonna be enough to make the best use of crit burst dmg. And that will hurt you. This might work, BUT builds work best on synergy, not just the items that look bad-***.

I admit Warmongers and Frozen Mallet give you great health, and health regen, but if those are the core to your build, you have to find something that will work with them. I suggest Atma's Impaler. It puts that massive health to good use. Change the PD into Atma's, making the build cheaper, that lets you keep Zerker's Greaves. And turn Seals and Glyphs into flat health. This will increase the dmg from Atma's.

I would change the Masteries a lil bit too. In offensive I would add one more point in Sorcery. In defensive Id max out Hardened Skin and Resistance. Faster CDs, less dmg taken and more MR will help you survive longer.

IDK if this is the kind of feedback you wanted, but here it is. Im no gonna downrate this though. I can see alot of potential