Aatrox – the time of Darkins is over
Aatrox was nerfed in League patch 9.12, but not as hard as it may look at the first glance. His passive had too small cooldown during the laning stage and was too strong during the late game, so the cooldown of this ability was increased. But the real problem is the nerf of a healing bonus from his Ultimate ability. So, with this change, now you cannot play 2v8 in pair with Yuumi so you can still use this combination, as boosters of the cheap League of Legends boost service do.
That affects his laning stage, making harder the trading process with an enemy. His durability will be felt a bit smaller, but this still a great champion to boost Elo in League of Legends.
Ashe – make Ashe great again!
I don’t even know what to say. She was in an S-tier already as a core champion for your team, but with these buff (the cooldown of an active ability decreased), Ashe becomes only stronger. Maybe Riot is planning something interesting, like buff some champions that are incredibly good against Ashe.
Caitlyn – just right click them, LOL
The buff of the base attack damage will be great for those who maining this champion. Caitlyn CSing skills increased a little, so I think that she will find her place in this meta. But her overall strength is not changed. She is still a pretty weak choice for a core champion.
Irelia was too good in the pro stage
Irelia showed too much dominance in professional games and, as we know, this is never leading to a positive outcome. Her cooldown of E ability was increased, while the range was decreased. This will hit her hard, Irelia will lose a lot of possibilities to early kill a lane opponent. And this will hit hard her snowballing potential.
At the High-Elo she never was a top priority pick, but with that nerf, many players will forget about her. This will hit her popularity in the middle and low brackets in the same way and even higher