Aatrox is not broken

Mid-Patch
BASE ARMOR : [33] ⇒ 38
BASE HEALTH GROWTH : [80] ⇒ 90
PASSIVE DAMAGE AND HEALING :	[5-10%]
⇒	5-12%	(based on level) of the target's maximum health
The Darkin Blade.png Q - The Darkin Blade
FIRST SWING AD RATIO :	[55/60/65/70/75%]
⇒	60/65/70/75/80%
Patch 9.9
Passive attack now also heals Aatrox and mutilation removed. Q cooldown adjusted and damage increased. W slow flattened and cooldown increased. E heal trigger adjusted. Revive no longer a baseline effect on R. Takedowns now extend R and enable revive, movement speed adjusted, increases healing. LOTS of tuning… Just read the full changelist for this one.
Where do we even begin? Since his rework, Aatrox has settled into a diving, one-shot playstyle that’s protected by the guaranteed safety of a revive. Rather than number tuning to make the revive less powerful, we’re making mechanics changes across the board to even the scales between reliable power that's valued in pro and power that's more fitting of Aatrox’s fantasy. Most notably, the revive on his ultimate is much less reliable, freeing up a lot of room to give him buffs (which make up the majority of the other changes here). Overall, this patch pushes Aatrox toward a more bruisery, drain-tanky playstyle and his list of strengths will include more than one, all-in dive combo, accentuating his thematic as a life-draining war machine.

Base Stats
HEALTH REGEN : [8] ⇒ 3
Deathbringer Stance.png Passive - Deathbringer Stance
MUTILATION Aatrox no longer reduces healing and shielding on champions
I NEED HEALING Heals Aatrox for bonus physical damage dealt
BONUS DAMAGE :	[8-16%]
⇒	5-10%	(lvl 1-18) of the target's maximum health
COOLDOWN : [25] ⇒ 15 seconds
COOLDOWN REFUND : [2 seconds per ability cast and per champion hit with the edge of the Darkin Blade] ⇒ 2 seconds per attack or ability hit on enemy champions and large monsters and per champion hit with the edge of the Darkin Blade
MAXIMUM DAMAGE VS MONSTERS : [400] ⇒ 100
PICTURE PERFECT : Attack frame adjusted to better match Aatrox's basic attacks
The Darkin Blade.png Q - The Darkin Blade
COOLDOWN TIMER START : [On first cast] ⇒ After Q3 cast or after Q cast window expires
COOLDOWN :	[16/15/14/13/12]
⇒	14/12/10/8/6
DAMAGE :	[10/25/40/55/70]
⇒	10/30/50/70/90
Infernal Chains.png W - Infernal Chains
SLOW :	[15/20/25/30/35%]
⇒	25% at all ranks
COOLDOWN :	[18/17/16/15/14]
⇒	26/23/20/17/14
Umbral Dash.png E - Umbral Dash
ATTACK DAMAGE No longer grants 15/25/35/45/55 attack damage for 1.5 seconds
HEAL TRIGGER : [Physical damage vs champions] ⇒ Any non-periodic damage vs champions (heal percentages unchanged)
World Ender.png R - World Ender
FREEVIVE Taking lethal damage during World Ender no longer revives Aatrox over 3.25 seconds, unless...
GOT THE RESET Takedowns extend World Ender by 5 seconds, refresh its movement speed, and allow Aatrox to revive upon taking lethal damage while World Ender is active
AMNESIA Reviving no longer clears temporary buffs on Aatrox (e.g. Conqueror stacks)
MOVEMENT SPEED :	[120/180/240 flat for 1 second on cast and while out of combat during World Ender]
⇒	60/80/100% decaying over World Ender's duration
FRIENDLY FEAR Aatrox no longer fears nearby allied minions on cast
STAYIN' ALIVE Aatrox receives 40/55/70% increased healing during World Ender
COOLDOWN TIMER START : [After World Ender expires] ⇒ On cast
COOLDOWN :	[160/140/120]
⇒	140/120/100
CAST TIME : [0.5] ⇒ 0.25 seconds
SLOW DURING REVIVE : [25%] ⇒ 99%
HEAL DURING REVIVE :	[10-50% Aatrox's maximum health (based on Blood Well)]
⇒	30% Aatrox's maximum health