Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
Well, not only is this my first Irelia guide, it is also my first guide, ever.
Please bear with me as I try to make the best out of this and provide you guys with as much information as I can.
This build concentrates more into making Irelia a burst dps. I tend to stay away from crit chance and crit damage because I have a personal stigma against critical chance, it's not dependable enough for my liking.
Also, since Bladesurge cannot crit, it takes away from the big critical chance pizazz.
As far as runes go, I get the following:
Greater Mark of Desolation : Armor Pen runes help with Irelia's auto-attacks and also help with her Bladesurge damage, since it's physical.
Greater Seal of Vitality : Max HP/Level Seals give Irelia a bit of cushion HP; without them I personally feel she is way too squishy for a melee dps.
Greater Glyph of Cooldown Reduction : Flat CDR Glyphs let you use your skills faster and, more importantly, your ult, which can be a decent amount of healing in desperate times.
Greater Quint of Desolation : Same as Marks, adds a little bit more oomph to your Bladesurge.
Exhaust: This spell can be used both defensively and offensively. It can help you get away from that carry chasing you down the lane, but it can also be used as an extra slow. If you have a more offensive play style, you can change this for Ignite instead.
Flash: I use Flash mainly to quickly close the gap between me and an enemy, for that surprise Bladesurge followed by an Equilibrium Strike stun/slow. Alternately, you can use Flash to jump over walls to escape a gank.
For masteries I go a standard 21/9/0.
Here's a detailed explanation as to why I choose the following masteries.
Deadliness 3/3: Although I don't like critical chance, these points are better spent than on AP/level. Mainly just filler.
Cripple 1/1: Ninety percent of the time I run with Exhaust. This not only extends Exhaust's duration, but it also provides additional armor and magic penetration.
Sorcery 4/4: Extra CDR for a quicker Transcendent Blades.
Alacrity 4/4: Increased attack speed gives you better healing/true damage output from Hiten Style.
Archaic Knowledge 1/1: This gives extra damage to your Transcendent Blades which also ends up giving you more healing.
Sunder 3/3: More Armor Pen = Stronger Bladesurge.
Offensive Mastery 1/2: One point in this mainly as a filler, I feel the guaranteed 2 extra damage at all times on minions is worth more than 3.33% critical damage. Especially because I stay away from stacking crit chance.
Brute Force 3/3: Extra 3 damage gives you more Bladesurge damage, and a bit more autohit damage.
Havoc 1/1: A must have when going deep mastery, I really don't think I need to explain why 5% extra phys/magic damage is a good thing.
Resistance & Hardiness 3/3 : Extra MR/Armor will help you stay alive longer in the early game, which is Irelia's most vulnerable time.
Strength of Spirit 3/3: Since we get a Manamune, Trinity Force, and Banshee's Veil, you'll have enough mana to make this more lucrative than dodge chance.