His body suffered and broke apart little by little. Then there was a time during the trial that he crushed the skull of an enemy beneath his foot. His skull shattered in the real world and the light of his soul flame within his skull went out.
The next thing that took a hit is his flames of Chaos Accumulation. The reddish flame on top of his head activated on its own burning his reservoir of Accumulation to maintain the connection to his soul and keep him alive. He will surely die when the flame goes out.
The flame began to reduce. Its rate of reduction increased rapidly. The thing about Accumulation is that it cost more to use the longer you use it. It continued to decrease rapidly despite the flow of more because of the chaos that Aeternus has caused in the Zargoth plane. It has been a long time since demons invaded the Zargoth plane and the destruction his subordinates are causing is unprecedented. His impact on an entire plane has increased his Accumulation immensely and it is still doing it but it is not enough to save him.
The rate of replenishment of the flame couldn't keep up with the ever-increasing rate of depletion. The flame of Accumulation burned until it became a tiny mote of light. Then it suddenly stopped burning. Instead of reducing rapidly due to the cost of usage, it didn't reduce at all and it didn't go out. His reservoir of Accumulation has run out but it isn't needed to sustain Aeternus's connection to the world anymore. There are 8 others that have taken on that job.
The soul sphere within Aeternus's soul served as the next anchor for him. It connects him to the other clones of Legion. He is not alone. He is part of a much larger entity and his connection to this entity has granted him 8 anchors so he can continue the trial even without a body. Limbo cannot have his soul.
The small mote that the flame of Accumulation has become remained in its near-death state. It didn't increase or decrease. Aeternus is not dead yet, if his soul returns and can't regrow his body, then he might die. He is just in limbo, not dead yet. He continued the trial until it came to the time when he killed the pleading demon nobles that Helios gave to him to grow his mark of sin.
"Maybe I shouldn't have killed all of them." He joked as he felt the pain of his claymore cutting into their bodies.
The surroundings darkened after he was done with them.
The will of the abyss spoke. "You have fortitude. I have seen it. You deserve the mantle of King."
"I told you so," Aeternus said smugly.
"But what kind of king do you want to be? Do you want to be the king of the abyss, the king of demons, or the king of kings? Be careful what you choose. The weight of the crown is heavy, it is heavier the more powerful it is." The voice took on an Ominous tone, "You have been warned, so choose wisely."
Three crowns appeared in front of him. They all look identical like a ring of golden metal. They are more like golden hoops than crowns. The three of them represent the three types of demon kings possible. He has proven himself to be worthy of bearing the Authority of a king so now he must choose what type of Authority he wishes and what type of king he wants to become. The information of the three appeared in his mind through his mark of sin.
The king of the abyss is a representative of the abyss. He grows stronger by furthering the agenda of the abyssal which is bringing destruction to the mortal plane. As long as a king of the abyss has an army, they can wreak destruction on a plane and wipe out the mortals. If the mortals die out so do the gods but that's not the aim of the abyss. The abyss wants the plane to be destroyed by mother high heaven.
If a plane is not promising or productive enough, for example, if it doesn't have a divine race, then mother high heaven will destroy the plane. There is a reward for the king of the abyss each time a plane is scrapped because of his or her actions. They get more Authority that way and grow stronger.
There are other advantages to becoming a king of the abyss. The representative of the abyss can never die as long as the abyss exists and as long as they are still king of the abyss. They are granted immortality and will always be resurrected by the abyss.
It is all good except the demon king of the abyss has to get access to the mortal plane if they want to attack the mortals directly. They have to get past the divine plane which is a tall order if the gods of the plane are strong. Plus, the king can only grow stronger when they cause the destruction of the plane or when they sacrifice celestial gods to the abyss. They can't become stronger in any other way.
Their immortality also comes with strings attached. Kings of the abyss can never become demon gods. They will forever remain demon kings. This option is not for him since he aims to become a world ender which is after the rank of a demon god.
The second type of king, the king of demons, is an independent demon that rules demons. This kind of king will be able to form another plane in the abyss and it will be their personal domain in the abyss like the divine kingdom of gods in the divine plane. The entire plane will be their domain where they are strongest and where their surbodinates will stay. The plane will also give them a continuous supply of soldiers for their army.