Aatrox Rework Idea, spent 4 hours theorizing on this with my 2 high elo friends.

Passive - Living Blade (New) (2 passives)

Blood Well: Aatrox does not gain any health from life steal, but stores all life stolen in his blood well. Aatrox can hold up to (50-100% of Aatrox's max health, scaling with level) stolen health in his blood well at any given time. His blood well decays over 30-150 seconds (Scaling with level) when out of combat.

Idol of the Darkin: Upon taking damage that would be fatal to Aatrox, his living sword enrages and protects him from death, granting him a decaying shield for 100% of the health stored in the blood well for 8 seconds. During this time, Aatrox doubles his lifesteal and can continue to store health in his blood well. All health stored in his blood well during this time will immediately be converted back into his shield. (225/175/125/75 Second CD, scaling with ultimate rank)

Aatrox can still fill his blood well while on cooldown, but will not gain the shield until it is off cooldown.

Q - Dark Flight | 24/21/18/15/12 Second CD

Aatrox leaps up and slams down at a target area, dealing 70/105/140/175/210 (+1.2 Bonus AD) Physical Damage and knocking up all units hit for 0.5-1.5 seconds, depending on how close they were to the center.

Leap animation sped up and smoothed out, reduced to 0.5~ seconds from 1~ second.

W - Life Siphon (New) | 12/11/10/9/8 Second CD (After Attacking)

Aatrox enhances his next basic attack within 4 seconds, dealing 35/60/85/110/135 (+0.3 AD) additional damage.

If he basic attacks an enemy champion, he marks them with Siphon for 2.5 seconds, causing all health they would receive from any source (besides health regen) to be negated and instead transferred to Aatrox's blood well.

Life Siphon acts as an auto attack reset.

E - Blades of Torment | 18/16/14/12/10 Second CD

Aatrox unleashes two converging energy waves, dealing 60/90/120/150/180 (+0.6 AD) (+0.8 AP) Magic Damage.

Enemies hit in the final 325 units of the energy waves take 150% damage and are slowed by 90% for 1 second.

Final 325 units coincide perfectly with the max cast range of Dark Flight, allowing you to engage easily by landing your E from max range.

R - Massacre | Blood well must be off cooldown to use, puts blood well on cooldown.

Aatrox's blade unleashes a dark pulse, dealing 200/300/400 (+1.5 Bonus AD) Physical Damage to nearby enemy champions and filling his blood well by 10/15/20% for each champion hit.

Aatrox then consumes his blood well, and transforms into his True Darkin Form for 8 seconds, gaining 175 (350 Total) attack range, and 1% increased attack damage for each 2% of his max blood well was consumed.