Hello to my first guide of all time :)
Please read the whole guide before you judge it cause I haven't slept in some days and I worked really hard to make it look like this so please tell me what I did wrong if I did something wrong and I am gonna fix it and I am sorry for my bad English but this is because English is my third language and i will try to fix grammar issues after finishing the Guide and i really appreciate it if you give me feedback and help me out :)
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Back to the guide.This guide is focusing on not relying so much on your Highlander
to take down champion or turrets by getting much attack speed but while doing amazing amount of damage from your crits which with your full build will be 100%
Now let's go to the guide... Shall We?

Pros +Great Dps +Great Backdoor +Good Chase/Escape Ability

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Cons -So squishy -Countered by Hard CC -Can be kited easily

In here you will find all the viable rune choices on Master Yi

This rune setup will help you get early kills thanks to the Armor penetration and the bonus attack damage combined with wuju style and also the armor and magic resistance boost may save you from giving them first blood thanks to Blitzcrank's Rocket Grab

• Greater Mark of Attack Speed/ Greater Glyph of Attack Speed-Good choices on any ad carry (especially Sion:D)and pretty good on Master Yi if you are jungling but on this guide you already have 1.8 attack speed without Youmuu's Ghostblade's active or Highlander
  Greater Mark of Attack Damage- Can be a good choice if most of your enemies are carries and you don't need the extra armor penetration
• greater quintessence of desolation- I see many people get this with greater mark of desolation which I don't know what will they do with all this Armor Pen while they have no serious damage but it's you choice you can still get it if you like to
• Greater Glyph of Magic Resist- I forgot about this one .. this one is your own preference if you like to have strong defense against mages early game or late game it's your choice

This is where you will more details on why I choose this mastery and not the others

In here you are gonna know what Master Yi's spell do and their importance for you

• :Master Yi strikes twice every 7th basic attack.
  
  This is a great passive that will help you to last hit and save you from a bad 1v1 situation and helps you destroy turrets
• :Master Yi leaps across the battlefield striking up to 4 enemies, dealing 100/150/200/250/300 (+1) magic damage to each enemy with a 20/30/40/50/60% chance to deal 400 bonus magic damage to minions.
  
  This is your Gap closer and your only source of AoE damage and it has great base damage and it will you help you farm creeps very fast and it will speed up your jungle when you get it
• : Master Yi channels, restoring 140/280/420/560/700 (+4) health over 5 seconds. While channeling, Master Yi gains 100/150/200/250/300 armor and magic resistance.
  
  Amazing spell that if you used in the right moment you are invincible since it gives 300 armor and MR plus 700 hp
  Tip:Use this when the enemy team have used all their cc so they cannot stop you from the channeling
• :Passive: Increases physical damage by 15/20/25/30/35.
  Active: Master Yi can activate this ability to double its effectiveness for 10 seconds, but this removes the passive bonus until Wuju Style becomes available again.
  
  This is your bread and butter as AD gives you a great passive AD and when you activate it again the damage is doubled very good for early kills
• :Increases Master Yi's movement speed by 40% and Attack Speed by 40/60/80%, and he becomes immune to all slowing effects for 8/10/12 seconds. Additionally, killing a champion refreshes all of Master Yi's cooldowns. (Assists reduce half of the base cooldown amount.)
  
  Your ultimate ... most of the games when you hit lvl 6 you will be able to get one of teir team if he had less than 50% of his hp if you used it with your wuju style and it might even be a double kill since it refreshes on kills

Here I am gonna explain why I choose my skill sequence and the other viable skill sequences

This is my preferred set cause it gives you great damage output as soon as you get level 9 with your maxed E and your first phantom dancer or even zeal I rarely go this one but it's extremely useful if I am having really tough lane and I am getting outfarmed

• Berserker's Greaves-You need this item as fast you can for the bonus attack speed and movement speed bonus
• Phantom Dancer-We need this cause it gives amazing AS and Crit Chance bonus and it also gives you movement speed so it's a must
• Infinity Edge-This is a must!It gives you crit chance ,attack damage,crit damage this is a most after PD
• Bloodthirster-amazing item! it gives Huge Ad bonus and life steal once you get this one you can almost 2 hit the squishies
• Youmuu's Ghostblade-this is the last item you get it gives you everything and ad carry need :ar pen,cdr,ad,crit chance,and an active that increase your attack speed by 50% and movement speed by 20%.Do not forget to use the active it's so important!

This is not a full defence build but I am just gonna add some defensive items that you can replace with any item in the main build

• Mercury's Treads: You must get this if you are facing a hard CC team cause if you are Master Yi so you get focused hard.So if you didn't get this focusing you will be so much easier since you don't have any kind of cc reduction so in most of the game you can start with
  Berserker's Greaves and then sell it later and get mercury treads
  replace with: Berserker's Greaves(Duh)
• Guardian Angel:really important item on any carry that gets focused hard so it's really good on Master Yi it will make you a bit harder to kill and even if you were killed you will be back with a bit of hp and mp
  replace with: Youmuu's Ghostblade
  Tip:Don't get this in the same order as the youmuu's just get it when you need it
• Maw of Malmortius:great item against champs like Karthus it will save you from his ult Requiem countless of times you must get this if you are against him it will you give amazing amount of damage and defence and a great passive so just buy Hexdrinker as soon as possible and then make it MoM later
  replace with: Phantom Dancer or Youmuu's Ghostblade

This will include Summoner Spells that are viable on Master Yi

• :I choose this one cause it will help alot taking down a more fed Master Yi than you thanks to the physical damage reduction and it also give you a nice cc since you don't have any kind of cc
• :Many people this that it's too much but I think it's great summoner on Master Yi cause you are not always sure that you will get kills with your Highlander so sometimes you will need the extra movement speed so you can chase someone when your ult is down or escape from a gank after using you ultimate to destroy a turret.
  It will help you many times.

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• :Great choice for first blood and against champs like Warwick
• : Good summoner spell for wall jumping and going back to turret before you get killed but I still prefer Ghost over this one cause the wall jumping is not easy cause you might press it earlier than you should and you will end up dead and plus Ghost will give you overall more distance than Flash will do.

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• :Good summoner spell that will give more map awareness and team presence
• :This summoner as long as the enemy team have no healing reduction will help you in the laning phaze and your team in teamfights and will save you so much times and plus if you healed all your team then you will have free assists :D
  or]

If you played this game long enough you will know that mater yi is not a teamfighter since he have no cc at all and the only way to be a good team fighter is to go AP so you go in and let the enemy team focus you then you Meditate and your team comes in and kills them all.
Anyway as Ad Master Yi and especially with all this attack speed you will be a turret destroyer and pushing machine and you don't even need Highlander unless you know that the enemy team is coming and you have destroy the turret and run as fast as you can.
so if you are gonna backdoor then I am gonna tell you when to do it.

• In a bad teamfight situation where you were pushing bot lane while your team is getting killed in top lane and you know that your teammmates have a good escape mechanism then this is a perfect moment to go and take a turret or two since the enemy team will be so busy catching your teammates
  Note:Do not do this unless you are sure that your teammates can escape from the enemy team
• You are in a situation that the enemy team are at mid turret hugging and your team cannot attack them neither do the other team then you can go to top or bot lane and push as fast as you can and try to take a turret but if there was someone in the enemy team is waiting for you at the turret then it's time to call for your teammates to come with you and you gank him or you can go to mid again and make the tank go in and you go kill the rest of their team and then push and win.

So that's the end of it at least for now ...
I hope you enjoyed my short Master Yi guide and please if you liked it upvote it.It will mean so much to me cause it have taken alot of work from me to do this guide

-To jhoijhoi for her amazing guide Making A Guide you must check it out if you are gonna make a guide
-To Every Master Yi guide that inspired me to make this guide
-to Mintleaves for telling me how to center the words ! thx alot bro:)

In this chapter I am gonna write what I am looking forward to do such as uploading videos ,adding a jungle build and things like that :)
-finish the guide as soon as possible:done
-Add more details and upload more photos and fix grammar issues

2/9/12-4k Views.Awesome!:)

12/8/12-Guide was published
13/8/12-Added "masteries" chapter
13/8/12-Added "Ability explanation"&"Items" sections and changed some few things
15/8/12-Finished the guide
15/8/12-Changed the guide's name from "Double Strike OP(AS/Crit) (Under Construction)" to "Double Strike OP(AS/Crit)"