So...this is an off-tank Irelia build. I've been having great success with my build recently(link in summary) and just want to see what other people think. Try not to be too harsh, it's my first guide thingy too. Also I don't know to to put pictures or anything, lol.

Pros
-Great dmg even with just a trinity
-Able to close distance
-Self heals
-Does true dmg
-Able to farm well
-Has a CC
-Can change outcome of a fight with E

Cons
-Game is ruined if you can't farm well
-Somewhat squishy early game
-Most effective in a solo lane
-Slightly mana hungry early game (before philo stones)
-Not for people who panic at low hp
-Dies easily when focused

Armor pen increases the dmg of bladesurge and your ult. There is hardly any better alternative.

Flat armor helps with your early game since your goal is to farm and you will be harrassed.

Mr/lv helps your late game tankyness. If you know you're going to be laning against an AP champ that has strong harrass(IE Vlad,Ryze,ect.) then getting flat MR will help a lot.

0-9-21

Nothing beneficial in the offensive tree, the 15% magic pen will only help your E.

Grabbing the armor, mr, and hp/5 in the defense tree will really help your early game.

You get a buff to your ghost, exp boost, mana regen, buff time+, 3% ms, some cdr, and cdr on your summoner spells. Nothing in the other trees are as useful, but 21 in defense isn't terrible if that's your preference.

Not many people realize this, but gold per 10 is op. Starting off with a regrowth pendent lets you get a philo stone quickly. Once you have 715 gold, b and get your first philo stone and boots. Then ghost back to lane and continue to farm. When you have 800 you can b again and grab another philo stone. It's best to have them before 10 mins. Now that you have insane regen you can farm non stop.

When you reach 1260 get a sheen asap. A sheen will increase your burst by so much because it works with your q and you can proc it constantly with your ult. If you use your q sheen will instantly proc and apply it's affect on the bladesurge hit. Say you have 100 AD and lv 1 bladesurge, without counting for armor, it will do 220 dmg.

After sheen you need to start building a trinity force. Irelia benefits from practically every stat it gives and the great passives. Finish your boots too. Merc treads for normal situations OR Ninja tabi for heavy AD

Now that you have your trinity, you NEED to build tanky to survive teamfights. Otherwise you're just an Akali being stuck as the janitor. Depending on the team comp of the oposing team, you get either a randuin's or force of nature. 3-5 AP then force of neture. 3-5 AD randuins. If its a balanced team, either one will work. I usually get a randuins.

Once you finish the tank items, buying a wit's end is really good because attack speed synergizes well with hiten style, which is a good amount of your dmg. The 42 on-hit dmg is really nice too.

Last item could be an atma's OR guardian angel. An atma's gives you 50 ad and good crit and armor. If you're getting focused everytime you dash at their carry, it might be worthwhile to get a guardian angel. It SHOULD lower the concentration on you.

E first because of its great early game burst AND extra CC time. Bladesurge next because it also helps your burst but not as much. It also makes your farming much better. Hiten style last because you just don't get in enough auto's to make it worth it. Also an unlv'd bladesurge has an extremely long cd.

Ghost for running, chasing, getting back to your lane, and running to teamfights.

Ignite to boost your burst dmg.

Flash and exhaust are good alternatives. It's mainly preference.

Irelia's role in the team is to take somewhat less pressure off your tank and also be an anti-carry. Meaning in a teamfight your goal is to kill the carry. CC's will hardly keep you off their carry and with a distance closer Irelia is great at the role. With not many offensive items Irelia does insane dmg. This lets you build tank items to survive teamfights in melee range.

So yeah, I've only worked on this for~ 20mins so it's not super in-depth yet.

This is also my first guide, nothing fancy so don't hate too hard.

Current ranked stats with Irelia

http://imageshack.us/f/101/ireliau.png/