For RUNES I get Armor Penetration Marks, Dodge Seals, Cooldown Reduction Glyphs, and Armor Penetration Quintessenses. These runes proved to be the most effective during ALL phases through the game.

For Masteries I go 21/9/0 kinda standard.

Pros---
-Real OP.
-Tons of Damage.
-Tons of armor/resist.

Cons---
-Needs team if more than 1v2.
-Not really anymore than that.

These summoner spells are pretty much the only good ones for irelia. Other spells you can use are -- Flash and Cleanse but you need exhaust most definetely.

When you take the first step out of the summoners platform, make sure you get a regrowth pendant and a potion. When you lane make sure you take a solo, preferably top solo if you have a jungle. Usually you should lane until you get your first philosopher and then you get boots.

After your Philosopher Stones and boots, upgrade the boots to Merc Treads and get ready to build your Trinity force. You wanna get sheen so you can get the extra burst and mana then you can build the trinity force how you want, I go for the phage for the slow. After your trinity force get a Spirit visage, If they have alot of ap get your mantle before hp. After your spirit visage go for your Guardians Angel.

By now its late game and you should have no slots left. Sell philosopher stones one by one after you have enough to purchase a frozen mallet or Atmas impaler.

Please leave feedback on this so I can improve this build!