wanna know why aatrox sucks?
its because half of his kit depends on him being low hp, while the other half of his kit expends his HP.
with keystones(looking at you TLD), just about everyone's got enough burst to take an aatrox who's foolish enough to have half of his hp missing.
this forces aatrox to either build tank or get faceraped. and even when he builds tank, he's getting faceraped for the most part because he can't do any damage at all to even win a fight.
aatrox is just an extremely outdated kit that doesn't fit with riot's current garbage ideas of "EVERYTHING AND EVERYONE DIES IN ONE ROTATION HUE $$$$$$$$ICK PLAY$$$$"