April 26th 2011:
~ Added a "Teamwork" section.

April 27th 2011:
~ Added a "Skills" section for Yi. It explains about his spells.
~ Added a "Farming" section.

Alright! This is my guide to Master Yi, the master of disaster! Now, I'm sure you know who this guy is... He's the guy who was probably owning you in games from level 1-20 yeah? The guy you despised the most because you were running away at 100 HP after killing someone, got really close to the turret, but not close enough because Yi just so happened to Alpha Strike on a nearby minion, and sniped you to death without even losing HP! Yeah, he's annoying isn't he, the little samurai? XD

Anyway, you must be a new summoner to this game, because quite frankly, no one likes a Yi being played in level 20-30 games... Why? Because everyone just seems to do poorly with him... which is hard to believe since he's so GREAT at turning around games. But, you know, people get smarter as they get more experience, and it just so happens that everyone knows about Yi's abilities by level 20, since they've seen him so many times. That's not the case for me though... I still play Yi in level 30 games and I happen to believe no one has learnt anything from their early days as a noobie, as I get legendary status so quickly.

So yeah, this guide is gonna be focusing on helping experienced players (summoner levels above 20) play Yi. I really don't see any Yi's anymore, and when I do, they just suck at him, and make more players hate on him for feeding the other team. Anyway, enough of my introduction, let's go into Yi, the one who can make or break a game.

NOTE: I will be adding pictures soon. I just need to get used to this making a guide thing. First one you see haha.

Pros:
~ Powerful throughout the game (Early, Mid, Late... He owns them all!)
~ Awesome passive - Every 7 hits you do a double hit! Imagine having 320 damage and double hitting... That's 640 damage! Even higher if you Crit!)
~ He's a freaking samurai
~ An ultimate which goes off cooldown if you kill a Champion... Hello Pentakill!
~ Good harasser (Alpha Strike)
~ Good farmer
~ Has a backdoor (Highlander)
~ Can put down the other team's morale if fed (Surrender at 20)

Cons:
~ Low mana pool (Can't spam spells constantly)
~ Very squishy. Not a lot of survivability
~ Hard to play against experienced players with
~ Very item dependant

So yeah, I go with these particular runes when playing Yi:
Greater Mark of Desolation:
Armour Penetration, what's not to love? When you're building anyone AD, you almost always want to use armour penetration runes. I mean, when you are getting fed, the other team will start to build armour, which is bad for you, as it means they can survive longer to try and kick your ***! So counter with a bit of armour penetration in your grasp. Really useful stuff.

Greater Seal of Alacrity:
You will be building attack speed anyway, but it's nice to have an extra boost early game for when you're chasing down the other team in lane. Can be replaced for Dodge runes or even Mana Regen per 5/ per level runes - they can solve most of the problems with your mana pool. However, I don't bother with them, since you will be going back quite often to cash in on items. :P

Greater Glyph of Warding:
Gives you some magic resist, which is great, since casters are a pain for Master Yi, as they can harass him so easily! This can loosen the damage being done on him early game, and possibly save you later on (you get away from an AP caster with 10 HP - that's when you should thank the magic resist runes haha).

Greater Quintessence of Desolation:
The more armour penetration, the better haha. The fact they give +3.33 each means it's a staggering 10 armour penetration altogether! It may seem like very little, but an extra 10 damage every attack can mean the difference between an enemy running off with 30 HP or killing them due to the extra armor pen. Think.

If you have the runes, then great! If not, then you really should consider buying some of them, as they aren't just useful for Yi, but every other AD carry really.

Also, if you are one of those level 20 under, then you shouldn't bother looking at this section. I mean, don't even think of buying any runes under Tier 3, as it's a waste of Influence Points, and which could have been spent on Tier 3 runes. So yup, go away.

Alright, summoner spells. The ones I find most useful are Ghost and Exhaust.

Ghost:
It makes you run faster than you already are, which is a very nice bonus. Very useful early game when you haven't gathered that much movement speed, and allows you to keep on hitting an enemy champion without losing pace. It can help you get an early kill in all honesty.

Exhaust:
Compliments Ghost very well, as you use Ghost to catch up and use Exhaust on them as well so they can't run away from you so quickly. Plus, if you are fighting 1v1 against another AD carry, it can help you, an unfed champion, kill a fed champion. So yeah, only use it when you know you can get the kill. Otherwise, it's a 4 minute wait to use it again. :/

Anyway, I don't consider any other spells viable for Yi. I'm talking about spells like Flash, Clarity, Cleanse, Teleport... They don't contribute or compliment the way I think Yi should play as.

Now, with Yi, I go with a standar 21/0/9. If you not level 30 yet, and you are only level 20, then prioritise the Offence ladder, as that's where everything is useful for Yi. The critical chance is great on Yi, right up to the last tier, where your Critical Strike Damage is increased by 10% - NICE. Also, you put in that point in improving Exhaust - lowers the Magic Resistance and Armour of an enemy champion by 10... That's huge! It could help you get that kill ever so slightly quicker. Plus it's got a higher duration by 0.5 seconds, which is like WTF, awesome!

So yeah, the 9 points left are put in Utility, just to make Ghost a bit faster and a bit longer - great! Also, you have a low mana pool, as well as quite low health, so you really do want to get as much mana and health regeneration as possible. Only because you need to harass with Alpha Strike as often as possible, as well as heal from being harassed.

You will be getting buffs throughout the game when you are free from your lane. So the longer duration of buffs is good.

My Q, Alpha Strike, is my main harassing spell, so I try to max that first, putting aside leveling up my Ultimate, Highlander. I switch between Alpha Strike and Wuju Style, while I try to leave Meditate until after maxing everything else.

So it's really:
Highlander > Alpha Strike > Wuju Style > Meditate

It's common sense to level Highlander first, as it will be your main attacking ability, as well as escape mechanism. Meanwhile, Alpha Strike is next to have a large damage output when managing to hit them after bouncing off a minion. Wuju Style is next to increase your damage output, and to be used to get that extra bit of damage. Now Meditate... Here's something I need explain.

Meditate: Why don't I level it up by even one level early game?
Hmm... This is one thing I don't like about Master Yi... That one of his spells is healing himself... He isn't a wuss! You would not expect such a spell on a samurai... I've seen loads of Master Yi's that level this spell once, and quite frankly, I don't find it useful. Sure, it's nice to have if you are building an AP Yi, but on AD Yi's, it sucks. You don't have any AP, so you don't heal much at all, so trying to tower dive, kill someone, then Meditating does not work, as the turrets deal more damage than you heal. Plus, the spell itself uses a lot of mana, which is bad, as Yi already has a small mana pool, and needs to use his mana for ATTACKING. Rant over. Meditate sucks on an AD Yi, and can't save you. If you are playing an AP Yi though, then go ahead... It's only one of the two spells that are useful on an AP Yi.

Alright, I start off with a Boots of Speed and 3 Healing Potions. Now, you may be thinking... That's a bad idea :/ You want a Doran's Blade... Or a Dagger for that extra attack speed... But think again. Look, when you are Yi, you are almost always against a ranged carry or AP caster, which is BAD for him. Even with the extra damage from Doran's Blade or even the attack speed from Dagger does not help, if he is constantly harassed and at low HP. So yeah, I want that pair of boots to have an advantage in terms of dodging spells or running away from an auto attack. Plus, not only that, I want those 3 Health Potions to stay in lane a bit longer and allow myself to farm up, even if it does mean a few auto attacks from the other team.

Anyway, I have to say, it is hard to get an early kill with Yi. So what I usually do is farm up enough for Berserker Greaves and a Dagger, before returning to base. That's when I start being aggressive as Yi.

Anyway continuing on, I build a Zeal, before I start on an Infinity Blade. Next, I build my Zeal into a Phantom Dancer, before getting a Vampiric Scepter for some lifesteal to go with my high attack speed and damage.

That's then built into a Bloodthirster, before I continue to make another Phantom Dancer, as Yi looooves movement speed and attack speed. If the game hasn't finished already, I'd consider getting another Bloodthirster, so you have a pretty sickening amount of damage output and lifesteal.

Of course, this is the kind of build you want to get, though not everything goes to plan. If you are being targeted in teamfights for example, you want to get some surviability items just so you can't die that easily. I mean, you might die in the end, but surviving that bit longer gives you time to attack, and also your team to attack, so for all we know, you die, but everyone else on the other team does too!

Items such as Banshee's Veil is great on Yi, and sometimes I go for Force of Nature if the team have a fed AP caster. If the other team has a fed AD carry though, I'd start on a Thornmail or maybe a Sunfire Cape. Whatever floats your boat really.

Master Yi's spells are probably the most useful when you are in a 1v1 fight. You may already have seen them in action, or you may be that new guy who just likes his dangerous look. Let me just say, he is devestating with these spells. They are:

Alpha Strike:
This is your main harassing skill in lane. Why can it be used to harass? Well, in laning phase, you will have minions fighting each other, so it gives you the opportunity to use this skill on an enemy minion. This would cause you do a massive flash across several other minions, and it an enemy champion may just be standing nearby. It hits the champion, and there: harassment done. They can't harass you back, you are back to your starting position at the end, which is too far away. Harass. Very powerful skill.

Also, it's great to use when you want to clear minion waves. There is a small chance it does 500 damage on minions, which means an Alpha Strike could (if you are lucky) kill all of the minions in one foul swoop. So it's a great farming tool throughout the game.

It sounds great, but it is a skill that takes up quite a bit of your mana pool. This is a problem when you are in the early phase of the game, so really, you don't want to spam this spell too much - I usually use it then wait until I regain the mana I lost to use it again. But if you have a support champion with Clarity on your lane, then forget what I said here lol. Later on mid game, you'll be going around getting Blue Buff anyway, so mana will not be an issue really.

One more thing: this spell can also be used to catch up to enemies. Its range is quite large, so any gaps between your enemy, you can flash right up to him/her with this. You can use it on minions in your way to get a bit closer, etc.

Meditate:
It heals you for a certain amount slowly. For AD Yi, really not worth leveling up until later on in the game, as you have no AP, which means the amount you get healed for is squat. It's great for AP Yis though, as they can tower dive people using this. My way of playing Yi is no Meditate until level 15 or so. I mean, you will be gaining a lot of lifesteal from buying Bloodthirsters, so a heal is not necessary. It can save your *** though sometimse late game. (April 27th, I got a record 22/8/17 without even using Meditate once throughout the game).

Wuju Style:
Now I love this spell. It gives you a passive amount of damage every time you level it up, which is from 15 (Level 1) to 35 (Level 5), which is basically a Pickaxe and Long Sword. The best thing is when you activate it, you get twice the passive amount, so at level 5, you get 70 damage... That's nearly an Infinity Edge there! It's one of the reasons why I don't buy any damage output items early game and just focus on attack & movement speed. I mean, it provides plenty enough, and you'll be getting so many kills, you won't even have to wait long to start on your IE.

Now, I'd recommend avoiding using this spell, unless you are in a 1v1 fight and set on killing someone. Why? Because once the active wears off, your passive damage is GONE. And that's for 15 seconds, until the cooldown on the spell is gone. So yeah, don't try to use it early game, as 15 seconds is quite a long time (in terms of laning phase). Great spell nonetheless.

Highlander:
Now this is the spell that makes Yi what he is. "WTF YI JUST DESTROYED OUR TURRET IN 5 SECONDS AND RAN AWAY SO FAST!!"

"DID YI JUST GET A PENTA KILL? OMFG!"

These are the kind of comments you'd expect from the enemy team, as it's what makes Yi, Yi. It's his signature move - Yi is nothing without speed.

So yeah, let me talk about this ultimate... It is devestating, let me just say. The main reason Yi's get penta kills so easily.

So, Yi gains extra attack and movement speed over a period of time, and can't be slowed as well in the process. THAT. IS. HUGE. It means casters with Rylai's Scepter won't be able to slow you. Or Trundle's mud pit thing. Or Teemo's mushrooms. He can't be slowed by anything, which makes it a great escape mechanism. The fact if you didn't build any Phantom Dancers for that extra movement speed does not matter, as you have this ultimate to add it on for you. So yeah, it's an escape method for Yi. What else is it?

Well, it's a weapon of mass destruction as well, that's what. You gain attack speed with this baby as well, and that, added in with that extra movement speed is GREAT for chasing and killing enemy champions QUICKLY. You add in your other spells, then it is a guaranteed kill. And one more thing that makes Yi, probably the strongest AD carry in the game, is it reduces all your cooldowns, if you get a kill. That's right. You can do the whole process again... on another enemy champion!! That is bad news for the guy running away at 100 HP, after his team mate sacrificed himself/herself to save him. It would have been all in vain, because this ultimate, if still activated killing a champion, will take its cooldown away, as well as the rest of the spells. Devestating.

Like every other champion, you have to get used to one's attack animation to know when to last hit minions. With Yi, this is slightly easier, as you have quite a lot of attack speed from the start, even without any items boosting it. Also, as Wuju Style gives you increased passive damage, as the game progresses, it gets even easier to farm.

Anyway, your main farming tool is Alpha Strike, so really you want to wait until all the enemy minions are around half health or so, before using it. A bonus is doing it when an enemy champion is nearby to take a hit too. Besides your Q spell, every other spell should not be used to farm. You want to save your mana for one reason, and also, you want your ultimate, as well as Wuju Style off cooldown, incase a chance to get a kill appears. Even without Alpha Strike, it's fairly easy to learn to last hit creeps.

As I said, you want to be farming up in the jungle, in order to collect enough gold for items. Yi is nothing without his Phantom Dancers, in all retrospect. Also, you want to have red buff on you at all times. The fact it offers a slow if you hit an enemy is extremely valuable on AD champions, especially on Yi, as I'm not building any slow items in this build. Blue buff is also necessary for the pentakill you want to achieve: I mean, you need to kill 5 champions, which means you need to activate your Ultimate 5 TIMES. This requires mana, and well... Even at level 18, you won't have the mana pool to do this, especially as you will also be using your other spells to take down champions as fast as possible.

That's really it in terms of farming though. Whenever you find an opportunity, farm up. You need those items, and you need it FAST (only because you want to get an early advantage, before your enemies are able to get enough gold to counter you (Thornmail, etc)).

This is one of the aspects many Master Yi players fail at doing... And that's team fights. I'm sure you will know how to do those easy 1v1s, but how about 5v5s? Do you know how to contribute to winning the team fight? I'm pretty sure many regular Yi players do not. Why is it so hard? Because EVERYONE wants a piece of Yi, ya hear?

Alright, team fight starts Mid Lane, you are quite fed (10 kills) from facing off in 1v1s with the other team... But this is your first team fight in the game, and you are confident, you think you will be able to destroy the other team before they can touch you... Well... Sorry to burst your bubble, but you just died 2 seconds into the fight. You don't know what happened, you are upset they destroyed your kill streak, and are wondering HOW DID THEY KILL ME!?!

Simple. You are fed. You casually walk in with your team, who are not fed. So of course, they obviously target YOU, the annoying carry, who gave the other team several deaths.

So what am I trying to say? I'm saying, you won't stand a chance if you run in with the rest of your team. It's almost the same thing Fiddlestick's do in a teamfight... They wait it out, until the other team have wasted their ultimates before jumping in with his annoying ultimate.

So yeah, that's what you want to do with Yi. Wait it out. Wait until they are just focusing on the other team members, before you go in with Highlander and Alpha Strike. That is one way of owning with a Yi.

So that's my build for Yi, which is, in my own opinion, probably the most you can get out of a Yi. I mean, you have the attack speed, the movement speed, the critical chance... the DAMAGE! Everything that can help you catch up to your enemies, and annihilate everyone in sight. If you play Yi smart, which is what's key with him, you will consistently be the carry for your team. I made this guide just to show it is possible.

Anyway, thanks for reading my guide, and I hope it helped think of Yi in a different light - not the guy who feeds everyone, but the reason why the game went from 5-30 to 40-30 and ended in you winning.

P.S: I will be updating this guide to make it better looking! I know it looks shabby at the moment, as it has no pictures, YouTube links, anything whatsoever. So yeah, please wait patiently while I try to fix it up a bit. Thanks!