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.
Difference between Build 1 and Build 2
Build 1 is more of a tanky health regen ******** meanwhile build 2 is more of a damage oriented free win. The runes are also very different with Build 1 being more raw damage so level 1 you can one shot the enemy laner. Build 2's runepage is more of a anal penetration build.
Either build is broken as ****, so have fun 1v5 pentakilling all game =)
Okay, okay you want an actual Illaoi guide?
During lane phase everytime your e is up, hit it on your laner and watch them have to play a minigame while you can peacefully farm.
During teamfights, just mash your keyboard. Start your faceroll with a good ultimate and you already won the teamfight. Even if your team is down 30k gold, you'll still get a free win.