I've always thought my Master Yi build was good so I decided to try posting it.
Please do not judge my decisions that I haven't explained yet, like runes.
I want many people to try this guide, so before you thumbs up :D, or down :( think a bit because I only posted this on may 5 (today) and I don't have much time to write all the things.

I would more than appreciate it if you would show this build to your friends who play League Of Legends

Thank you, PainlessDemon.

Some may think my skill sequence is odd, or unusual.
I personaly think taking is a good idea, you start off with 55 AD, Doran's Blade adds 10 AD (66), and Wuju Style adds 15 AD - 81 AD at level 1. And that is without including runes and masteries.
If you buy flat AD runes and the masteries as I wrote, you start off with 106 AD - an average 5 hits to kill a level 1 champion.
Next I take for the minions and harass.
At level 3 I take in order to stay in lane longer and be able to restore about 150 HP every 35 seconds.
Of course is your first priority as your ultimate, you put points in it when you can; at levels: 6, 11 and 16
I max second, for the damage in teamfights, 1v1s and faster farming.
Next is for more damage and faster farming and jungling. (when maxed Alpha Strike has a 60% chance to deal an extra 400 damage to minions and monsters - without investing AP that is 700 damage per Alpha Strike) levels 10-13 are about when laning phase ends and you can roam around the map and jungle more.
The last skill we can put points in is , this gives you a 700 heal at level 18 and gaining 300 armor and MR while doing so.
I chose to max Meditate last because it is the only skill which does not help you deal more damage.

The items I choose are pretty basic.
Doran's Blade I start with a Dorans Blade; it gives you all you need at level 1: HP, damage and a bit of lifesteal.
Berserker's Greaves My next item is Berserker's Greaves, which is my casual item for AD carries - it gives attack speed.
Vampiric Scepter this item is for lifesteal, which gives more durability in fights and the ability to stay in lane longer.
Phantom Dancer Phantom Dancer these give movement speed, attack speed and critical chance, those and the Vampiric Scepter, combined with your Highlander (Ultimate), gives you extremely high durability in teamfights compared to your teammates and enemies.
NOTE: At this point of the game you will have a very high damage output and will easily be able to kill champions and get more fed which will lead you to buying more items and getting even MORE fed :D
Bloodthirster One of the best AD carry items, gives higher attack damage, higher lifesteal and the passive which gives you more AD and life steal (easy farm with Alpha Strike )
Infinity Edge This is one of the best late game items, and one of your main goals, you already have 60% critical chance from the two Phantom Dancers and the 25% bonus you get from Infinity Edge, combined with your amazing attack speed from Highlander, damage from Bloodthirster and Wuju Style will give you EXTREMELY high damage - 85% critical strike chance, about 350 AD, and an extra 50% critical damage from Infinity Edge.
If I would do the math, each hit you do, considering you maxed your Bloodthirster, you would do a crit about every 9 out of 10 attacks, each one dealing 250% more than it should - 200% damage=crit + 50% from Infinity Edge so... 350 (about base damage) divided by two is 175 and 350*2 is 700, so we add 175 (50% crit) and 700 (regular crit), and together we have 875 almost each hit, and with Highlander you have 2XX% attack speed, which is 2 attacks per second, and each attack 875-1750 damage per second. A LOT of damage.
Bloodthirster I buy a second bloodthirster for more damage and of course, lifesteal - as explained before. (when fully stacked Bloodthirster you get 100 ad and 20% lifesteal from it)
[*] Sell Berserker's Greaves and buy another Phantom Dancer I dont usually do this, because I think movement speed is very important with Master Yi.
But if you do decide to sell Berserker's Greaves and buy another Phantom Dancer you will crit each hit and have EXTREMELY high attack speed together with Highlander.

The masteries I go for are 24/0/6.
doing so, I attempt to achieve the highest damage possible at level 1. (I chose all of the masteries that give AD carries extra damage)

Pros:

• High damage output along all the game.
• easy farm with Alpha Strike.
• Highlander is great for escapes and also chases.
• One of the highest possible damage dealers in level 1.
• Meditate is a great tool for being tower dived or just wanting to stay in lane longer - armor and HP.
• VERY high attack and movement speed.

Cons:

• A bit squishy.
• Usually focused on.
• If you are stunned in a teamfight, you're dead.
• Needs to be fed in order to be usefull. (you might say this about any character, but, for instance Kennen's Slicing Maelstrom provides stuns in teamfights because of Mark of the Storm and Kennen's Electrical Surge. These all provide AOE damage and stuns without moving and being extremely fed).