"After many years of desperate battle, Aatrox and his brethren finally halted the Void's perverse advance, and seared the largest rifts shut."
Spatial manip for being able to close rifts torn in space?
"A force greater than a thousand dead suns pulled him inside the sword he had carried into battle countless times, and forever bound his immortal essence to it. The weapon was a prison, sealing his consciousness in suffocating, eternal darkness, robbing him even of the ability to die."
A nice description of Zoe's sealing
"Aatrox seized upon this opportunity, forcing his will and an imitation of his original form onto his bearer, though the process quickly drained all life from the new body."
Some justification for the tiers of those Aatrox sees as worthy vessels, you have to be powerful enough in your own right to be capable of handling the power of Aatrox's form
"In the years that followed, Aatrox groomed many more hosts—men and women of exceptional vitality or fortitude. Though his grasp of such magics had been limited in life, he learned to take control of a mortal in the span of single breath."
Dont know why they dont have it but all Darkin should have possession
"and in battle he discovered he could feast on his victims to build himself ever larger and stronger."
Aatrox can make himself larger and stronger the more he kills
"Darkness.
The breath I cannot take plagues me.
It is an emptiness in my lungs and throat. As if I had stopped mid-breath, and then held my lungs cruelly waiting. My mouth open, throat hollow, unable to pull in air. My chest, the horrible tension on my thorax.
My limbs and muscles refuse to move. I cannot breath. I am choking. The pressure builds. The stillness spreads to my chest and limbs. I want to scream, to tear at my face, to wail—but I am trapped. I cannot move. I cannot move.
Darkness.
I must remember. I must remem—
The battle. I lost control. It was foolish. The mortals formed in ranks against me. I crashed into them. Drank from them. The temptation was too great. As I reaped, I reforged their flesh into a better approximation of my true shape. Desperately, I consumed more and more, hoping for the briefest echo of what I once was. Instead, like a fire, I burned too quickly, destroying even my host's form."
More proof, as well as more proof of the Host needing to be powerful enough to handle that of an Ascendant
"I will drink from that city, but I will achieve only a grotesque mockery of my former glory. I was shaped by the stars, and the purity of my aspect. I was light and reason given shape. I defended this world in the greatest battles ever known. Now, blood and ichor drips from this stolen flesh as it decays. The muscles and bones struggle, tear, and protest the abomination I have become."
Proof of direct scaling between Aspects and Ascendants, also Aatrox has fought and beaten Pantheon in the past
"Rhaast will be disappointed," she said, her voice a wet, reptile hiss. "He had sworn to slay Xuuyan himself." Her venom blinded life-bearers shuffled behind her, unsure of what to do now that their reviled goddess had spoken aloud."
Rhaast had the power to kill another Ascendant