Diana or irelia

do you like assassinating people? diana do you like being a bruiser? irelia

If you're looking to tilt people and one-shot buy Diana. If you want a new main or something to play in ranked buy Irelia.

So probably Diana.

Diana for the obvious moon praising and cool gameplay, especially if you practice her R+Q combo for the reset.

Irelia if you want to finish Trinity Force and start one shotting ADCs with a single E-W-Q rotation.