Just playing Aatrox once and I saw
#His ult gives him 20% blood pool for each enemy champion hit that must be really useful when I jump into 5 without any attack speed steroid from my blood well and hope I can hit all 5 with my 175 range ult.
#His passive revive
gives more than enough time to reposition an entire team and plop CC to instantly kill the 1/5 HP aatrox with** no AS sterioid from blood well**
Must be really useful never. Would be like respawning from
and getting immediately exhausted.
#His E and Q are his only forms of sticking to an enemy and have 10-14 second cooldowns while being extremely hard to land
#His W
Is his only form of sustain, while also being his only form of damage
The most counter productive thing I've ever seen.
One form damages him so that he needs even more sustain that he's already in desperate need of , and the other gives sustain. Highly dependent on 
These are his major issues that make him feel clunky/not viable.