I didn't even plan on writing this. A while ago I played her when she was free and I didn't like her at all. She didn't have enough damage for me until later in the game and then I felt she was to squishy. I was building her like almost everyone else did, but she just sucked. Now, trying a different build, I find that I was horribly mistaken.

I do not like her as a Burst assassin like Akali. I do not like her as a dps like olaf. I like her as a Rambo. An in-your-face killer. You will not see the damage output of some builds. However, you will be able to take a punch and live. And, if you target the right people, you will kill them easily.

This build, however, takes a decent amount of farm to achieve. If you have a solo lane you're going to be a monster. If not, you're just going to be another person.

Pro's

You can 1v1 almost anyone as soon as you get Trinity.
Your Q can be spammed to farm easily.
Has built in heal
Has built in CC
Tanky as hell
Nice burst damage
CC is next to useless against her
Good candidate for an oracle

Con's

Requires solo lane for income
Relatively expensive build

I generally don't like posting my game history because it seems like a type of bragging to me, but since I think a lot of people will be wary I feel like it's necessary.

The Custom game you see was my first ever game as Irelia. This is what I proceeded to do.

As you can see, my first 4 games with Irelia were good. I do, however, need to work on her a bit though. Also, I apologize for not selecting one of the matches so you could see the build. You're just going to have to trust me.

I fell in love with this runes set a while back and it quickly became my new favorite. On any solo lane it is good, but she makes it great.

The Greater Mark of Desolation gives you the pen that greatly increases your late game damage while helping your early game as well. They are pretty standard mark for any AD type damager.

The Greater Seal of Resiliance gives flat armor. This REALLY helps with early game harass. It makes you way tankier and therefor much more menecing. Some people will trade these for Greater Seal of Evasion. They will be of much more benefit late game as you will be dodging 300+ damage shots, but, especially in non-ranked, I find that the more I do to help my early game the better my late game will be. Personal choice. Basically, in my opinion the higher level your play the more I would lean toward dodge.

The Greater Glyph of Magic Resist bumps up your MR. Pretty much the same function as the seals but it blocks magic damage instead. Obviously.

The Greater Quintessence of Vigor is what makes this build though. They give a decent chunk of HP Regen that helps sooo much with your laning. I was hesitant to buy them, but they are great.

As asked by a commenter I will explain my choices.

I will use a lane against Ashe as an example. I know that it isn't probable, but I want use a character that builds heavy damage as an example.

As with every character ult takes precedence. It does loads of damage, and in this case, heals you as well. I don't know of any characters in the game except Karma and Udyr that would be different, but that is only because their ults function differently.

So that means (ults aside) that we have to prioritize the other three.

Her Q does some damage, is great for initiation, and is great for last hitting since the CD refreshes.

Her W gives her health for every melee attack and will briefly give true damage upon activation.

Her E does damage and applies a slow/stun depending on the situation.

Q is great to cover distance to the target and to last hit but both of those don't need more than a point to obtain. Since E does more damage per level AND has an increase in CC length it takes precedence over flat damage. So, as of right now we have R>E>Q

W gives health on attack and True Damage. This is where my Ashe example comes into play.

Ashe being a ranged character will harass you often when you go to last hit. The on hit life greatly benefits you and keeps you in lane since you will be harassed so much. At level 5, you will be gaining around 22 health back for every attack. That, combined with your HP Regen due to your Runes/Masteries, makes you crazy sustainable. Your W is basically a Wriggles as far as health return is concerned.

However Ashe just bought her boots and a new shiny bf sword. Scary right? No. She hits you for the 150 damage. However, it has to bypass your resistances that you have. You have your W. This ability alone hits for 75 TRUE DAMAGE meaning they can't prevent it. Plus you have another 100 physical damage through your auto attack. And, if that wasn't enough, it heals you for 22 health on hit. Oh ya, and it is like that for 6 seconds.

So, the reason W takes priority is that it deals an obscene amount of damage and helps with survivability.

Your E comes before Q since it has more base damage and utility.

Your Q comes last since the best part about it is that you can last hit forever (though you should be doing this via melee since it heals you), and it is a gap closer. The damage isn't really that impressive.

R>W>E>Q

Pretty standard. Nothing really to say.

Everything is set up to increase damage and defense. Strength of Spirit ups HP Regen further. Especially after you get sheen.

Now, time for a bit of a rant that will hopefully give you newer players a heads up.

Almost every guide has a "Core Build." What this means is that you ignore EVERYTHING after it. Do not look at the pretty pictures after. This is why I hate giving more than the core build in guides. What happens after the core build is totally situational. The core is a static build. Something that will happen every game. After that it is up to the player to figure out what to do. Please, if you take nothing else out of this guide, take this. It will make you so much better.

*End Rant*

Now, to talk about my build. I like to start with a Regrowth Pendant and a health pot. This, with your runes and masteries, give about 31 HP Regen per 5 seconds at level 1. This, combined with your W's passive is crazy. If, for some reason you are still getting pushed around, you can throw a wriggles in there and you make that Warwick look like a pansey. However, you will really never need to.

The first trip back you should buy your Philosopher's Stone, Boots, and Heart of Gold. You may think, well damn that's a lot of stuff. Not, really. About the time you've saved up 1600 gold you can buy it all.

The boots are good for what boots do. They are really what this game revolves around.
The Philo Stone lets you basically spam your Q forever and never run out of mana. It also lets you harass so much more.
The Heart gives you the tankyness you need to destroy them.
Also, as a side note, you are getting another 2 gold per 5 seconds.

Now time for Trinity. If you are kicking in the teeth of your foe, grab a sheen first. This will make your burst worth another 100 or so minimum. Also, due to your masteries, your HP Regen goes up due to the increase in your mana pool. If you are losing or even in your lane I would grab a Phage. It gives health, damage, and a slow. It's great. Now finish your trinity.

THIS IS YOUR CORE BUILD. THE REST IS UP TO THE GAME TO DECIDE WHAT YOU BUILD.

I will however give suggestions as to where I go the majority of the time.

After this you should finish your boots. I mainly go merc's. This makes CC almost worthless on you due to your passive. Ninja Tabi are great in combination with the dodge seals discussed earlier. The only other viable choice might be Zerker's but I really don't like them on her. So, let us recap: if they have CC: Merc's. If you have dodge seals and they are heavy on AD: Ninja. If you don't need either: Zerker's.

At this point if you are tanky enough, I like to grab a Wit's End. This gives all the AS needed, a nice damage increase, and more tankyness.

If you need more resistances determine what type. I like Randuin's Omen or Force of Nature. You already have a chunk of Randuin's and the active is sweet. Force basically laughs at all magic users.

I usually grab Guardian Angel after. More resistance, 2 lives, more success.

If you are tanky enough, the only other damage item I would recommend would be Madred's Bloodrazor. However, I hardly get this.

You may think "Well damn Viscous, this is a tank build." And you are wrong. This is Trinity tanking. This, in itself, is another animal. You will be amazed when you try this how much damage trinity alone dishes out.

If you burst an Ashe, you will take her to 1/2-1/3 health instantly. If they run away LET THEM. I see to many people chasing. If Ashe leaves you have as good as killed one of their carries since they are no longer doing damage. Go pick on someone else. If that Ashe decides to walk back in, then by that time your Q is once again about off cooldown. Kill her this time. If you chase, even if you kill her relatively quickly, she is stealing your damage output since you are attacking no one while chasing her. Besides, I bet that Annie won't like you up in her face any more than Ashe did.

I thank you for reading this. I will post it early just to get it out there, but I'll be back making it look pretty and just all around polishing it. Constructive criticism is appreciated.

Since I sent this out early I will list all updates:

10/5/11 - Screwed up the skill sequence. Fixed.
10/5/11 - Added description as to why I chose skills I did.
10/5/11 - Added "finished build" on top for example.
10/5/11 - Finished up Pros and Cons