I've seen this text from Meddler (creator of Syndra, Varus, Lissandra and Ziggs) in a short League of Legends Q&A
from 5 Months ago:
> *What are your thoughts on Aatrox? He feels like he is in a horrible state and could use some buffs or a rework.*
> We'd like to do some significant work on Aatrox when we do a class update to diving fighters. Aatrox has a theme with an enormous amount of potential. At present, however, his gameplay is a bit generic, doing a mix of things plenty of other fighters also do. That means, unless he's the best at those things, he's not going to be the best pick gameplay wise. Our goal with an update, as a result, would be to make him more unique, taking advantage of his backstory and letting him bring some distinct tools to a team.
> We'd also like to do some work before then, both to help him out slightly (he's a little on the weak side) and at least start to push him in a more focused direction. At a rough guess, sometime around the pre-season is when we'll likely look at that.
> Meddler, Lead Game Designer
Nothing has happened since then (the last change on Aatrox was from Patch 5.11 in 2015).
Do you think they'll still do the buff or directly move on to the rework?
What did he mean with
> Our goal with an update, as a result, would be to make him more unique, taking advantage of his backstory and letting him bring some distinct tools to a team.
Here are the most important lines from his lore http://leagueoflegends.wikia.com/wiki/Aatrox:
> Aatrox is a legendary warrior, one of only five that remain of an ancient race known as the Darkin.
> Just when all hope seemed lost, Aatrox appeared among the ranks of the Protectorate. With but a few words, he urged the soldiers to fight to the last before throwing himself into battle. His presence inspired the desperate warriors. At first, they could only watch in awe as this unknown hero cleaved through their enemies, his body and blade moving in unison as if one being. Soon, the warriors found themselves imbued with a potent thirst for battle. They followed Aatrox into the fray, each fighting with the furious strength of ten until they had won a most unlikely victory.
> Over time, their memories of battle faded, only to be replaced with a grim revelation: their acts of heroism were, in fact, brutal atrocities committed by their own hands.
> Though these stories remember him as a savior in dark times, Aatrox's true legacy may be a world filled with conflict and strife.
Seems like he is supposed to be a teamfight champion, who does the engage and maybe boosts his team after getting poked to low HP or help his team to do a comeback in battle by other means.
Then he leaves a debuff after the battle though.
How would you make such a change?
Edit: He already got a PBE buff http://www.surrenderat20.net/2017/02/222-pbe-update.html#balance