Irelia Build Guide by ixFlash

I don't find the 2% CDR from Sorcery in the mastery tree is worth it as taking Weapon Expertise for the extra armour penetration.

Since you got Philosopher's Stone you could turn it into Shurelya's Reverie for the CDR as well as the active that makes you chase your target down easier. If you are going to get a Randuin's Omen, you may want to get Heart of Gold earlier in the game to maximise its passive and effectively buying the Randuin's Omen for much less gold.

I would probably get Guardian Angel a bit later simply because you won't be dieing as much at this stage. It is better to take say a Force of Nature if you are laning against an ap hero e.g. Akali to take minimal damage or a Randuin's Omen if you are laning against an AD DPS also take minimal damage

I see what you mean, and I thank you for your feedback, but the reason I take an early GA is because it gives you both armor and magic resist meaning if the game goes well and nobody is feeding you have a balanced kit. I you have your 4 core items I've listed then you should have a pretty survivability and damage with very little risk. The omens and FON are situational items. I agree with you on what to take when you line up the match ups.