0/21/9 to 9/21/0.
Better laning, able to be more aggressive in trades.

The reason i have gone with AD marks/quints is to fix Irelia's only weak phase. Laning. The AD marks/quints synergize quite well with her Hiten Style. The MR blues are for late game tankiness and the armor yellows are for the early game tankiness against top lane, which most of the time ends up being an AD.

These masteries focus on being the intiator for the team. The movement speed when above 70% hp is great for starting fights and also makes you able to chase the squishies. The final point in the defense tree makes you an unstoppable train, the final point + Mercury Treads + Ionian Fervor = 2 STRONK. The 9 in utility, Runic Affinity is also good for red buff. Sometimes you are better with red buff than your AD carry.

I like to start with boots, 3 pots for the early mobility and sustain. In certain situations you will need to buy a Null-Magic Mantle, ex. Akali Rumble. In other cases you may need to buy Cloth armor and 5 pots, to upgrade to an early Ninja Tabi, ex. Renekton, Gangplank, Olaf, and Pantheon Talon. The early Phage is great because of the early tankiness and damage. After getting that upgrading to either Mercury Treads/ Ninja Tabi is great. The Wit's End is one of the most important items on Irelia, building the MR from each attack and the attack speed + true damage from your W is just amazing damage. Getting the Giant's Belt after that will put you around 2.6k hp and you haven't even finish your Atma's Impaler Warmog's Armor/ Force of Nature. The AtMogs/FoN are also core items, both of these items give you 200-250 hp regen alone, that's without counting Hiten Style, and Wit's End.

Hiten Style first. Always, never max anything else first, no matter who your against.

Bladesurge > Equilibrium Strike
The reason i choose Bladesurge over Equilibrium Strike is because in team fights I find myself the one who kills the AD carry first, most AD carrys will have some sort of escape ability, so having your Bladesurge on a 3-5 second cooldown is just great for being able to stick on them.

Flash: Gets you out of near death situations, secures kills, OP.

Teleport: Gets you to teamfights, gets you back in lane early game.

Other viable summoners:
Ignite: Good with Hiten Style not really my kind of thing, but if you want to win lane, always good, also good against high-sustain champions. ex. Yorick, Nidalee Olaf.
Exhaust: Good for some situations, able to fight with escape, and/or get that clutch kill with very little hp. Also good against those champs that can harass you hard. ex. Pantheon, Garen, Renekton.
Heal: Used for bait, pretty much it.

Laning the worst part about Irelia, but if done right can you get the early kill and make you snowball out of control.

Last hitting: All that matters early game. One of the most vital things for Irelia is money, most of her items cost quite the amount so make sure you get the last hits. Irelia's Bladesurge is a last hitting ability but it shouldn't be used if you can just auto-attack the minion for the CS. Under tower if you have trouble getting the last hits you can always activate Hiten Style and use Bladesurge when needed.

FARM FARM FARM

Harassment: Usually you want to be within Equilibrium Strike before even harassing them.
How it should be done: Equilibrium Strike - Hiten Style - Auto Attack - Bladesurge - Auto Attack - Fall back (Unless you can for sure without a doubt get the kill)

Akali: I suggest starting with Null-Magic Mantle and playing very passive. The only time you will most likely be able to kill her is at level 9, where all hell will break loose, and late game.

Rumble: Same as Akali.

Cho'Gath: Won't do anything to you, against Cho it's more of a farm game, but start Boots 3 pots if he lanes a Q while the jungler is ganking you, it won't end well.

Darius: This guy, holy ****, I really don't know how you beat him right now, as of now I start Regrowth Pendant . Try and stay passive early game, and you can get aggressive once you hit 9, try and get as much cs impossible, auto-attack as much as possible just so you don't die. Don't trade with him, only at 4 and don't do it often. If he has Ignite STAY PASSIVE. Get Philosopher's stone and get Ninja Tabi . Also, when you're 6, watch your HP, he will kill you with Noxian Guillotine. Don't underestimate that.

Gangplank: Parrrley is dumb, can Scurvy your Equilibrium Strike. Start Cloth Armor 5 pots. Get Philosopher's stone, and get Ninja Tabi.

Garen: Watch for Decisive Strike Silence, back when he has you low but not super low where he can walk up to you and Demacian Justice your face in.

Jax: Meh, just the Counter Strike dodge is dumb, may need to get Wriggle's Lantern, start Boots 3 pots.

Lee Sin: GAAAAAY. Just farm avoid fighting him unless you have a jungler or mid with you.

Malphite: His Ground Slam will slow your attack speed. Don't go toe to toe with him. Get wards before 6 because his Unstoppable Force and a jungler, you'll usually die.

Nasus: Make him waste Wither and your fine.

Nidalee: AP - Javelin Toss AAAAAAAHHHHHHHHHHHHH. AD - beat her pre 6, or kill her level 9, your choice.

Mordekaiser: HUEHUEHUEHUEHUEHUE, get boots dodge that ******ed E.

Riven: Unless she uses Valor to get to you, don't fight her. Get Cloth Armor and upgrade to Ninja Tabi.

Singed: May need a Spirit Visage/ Chalice of Harmony, try and auto attack as much as possible for the HP. Get Boots so you can out run him.

Teemo: Blinding Dart, that's it.

Tryndamere: Harass him when you can. Deny him when you can. Kill him if he over extends or is reckless.

Yorick: Get Wriggle's Lantern, stay passive, you both can't kill each other, unless you screw up.

Warwick: He can kill you, you can't kill him unless he's ******ed. Go Boots of Speed]] 3 pots.

Xin Zhao: Cloth Armor get Ninja Tabi, make sure you get Phage as quick as possible.

Renekton: Don't ever fight him unless he wasted his second Slice and Dice and you have your Ninja Tabi, Phage, and Wit's End.

Wukong: Kill him early. Watch for those stupid decoys. Cloth Armor 5 pots.

Should have your Phage, Giant's Belt, Wit's End and your Mercury Treads/ Ninja Tabi.

Push your lane and start getting into little 2v2 3v3 fights and focus squishies, if you have your Sheen, they'll get chewed through.

You should always be the intiator.

Focus AD carry push them out of the fight.

Kill ALL the squishies.

You'll be quite strong with the full build.

If you have any questions about the build feel free to add me in game.
Summoner Name: TheGGongShow.

Any good Q&A will be posted below: