Massive Irelia E bug 100% reproducible, might be a small reason Irelia felt so strong pre hotfix
Using your E for some reason makes it so you kill 8 units, even if you use it on nothing.
The big problem with this is that it basically instantly gets you max stacks of Jaurim's Fist the moment you buy the item.
This also procs the speed from Phage, increasing her chase and fleeing potential.
Edit - I should note, it's the second portion of E
Edit 2 - This also works with Doran's Ring. Giving you 32 mana every time you cast E
Edit 3 - Also works with seekers armguard. So basically every unit killing mechanic in the game.