She is giving him 10 years to think about his choice. 10 years is a short time in a demon's lifespan but it is more than generous to make a decision.
Aeternus nodded and said, "How generous of you. I doubt that I'll need that long to make the decision. There's really only one choice to make isn't there?"
The demon lord was beginning to like where this was going. Aeternus's attitude pleased her. He seemed to have accepted his fate.
Then he suddenly stopped. There was a group of cloaked demons running toward the center of the plane. They are probably returning from honest hard work. They are high-rank demons and also all have the same boost under a certain ability called the Oath of a Lord. So they are honest and related demons coming from a day of honest hard work.
"What are you doing?" The demon lord screeched again.
"Giving you my decision to your offer," Aeternus said as he stretched forth a hand towards the group.
His hand was more like claws. His fingers were bony, thin, and sharp like blades. Dark Chaos flames formed from within the palm of his bladed hand into a massive ball about 1 meter in diameter while the demon lord threatened him not to harm those obviously "honest" demons.
"Honest" demons are rare in the abyss nowadays and she is simply advocating for their protection as a good, dutiful demon lord. He ignored her and threw the ball toward the group.
It flew and crashed into the ground like a meteor. They remained oblivious to the danger despite the several attempts of the demon lord to inform them. He had wrestled control of the area away from her and masked his presence. It is the same thing she did to hide the ambush team.
His chaos flame was stopping them from intuiting the attack, so they were caught unguarded by the attack and blown to bits. The flame gathered and returned to him in the sky with the energy and equipment of the demons he killed. His control of chaos energy has increased enough o prevent it from corroding several items.
"Is that answer enough for you?" He asked her.
Her voice was low as she asked him. "Why? I already reduced the conditions of the contract."
"I don't negotiate with terrorist."
She said to him, "I swear to make you regret this."
If there is one thing she abhors, it is having her things taken from her and Aeternus has been doing a lot of that recently. He has finally crossed the line.
"I doubt that. I very much doubt that." He answered as he began flying in another direction. The demon lord could tell where he is going.
"I am Beelta, a demon of gluttony, the Lord of the house of Dominance and the demon lord of the 541st plane of the abyss. What is your name insolent demon?"
"I am Khaos Aeternus, the eternal Chaos, the Chaos Bringer, and the worst enemy you could have made."
The demon lord laughed. "Who is to be my worst enemy? You? I don't think so. I crush bugs like you every time."
She utilized the control she had over the contract of the servants that she sent out to ambush Aeternus and killed all of them. Better to kill them herself than to have them taken from her."
Aeternus stopped when he couldn't sense their existence anymore. He could use his chaos Accumulation to track those he has affected in one way or the other. It felt like the fates of these entities are intertwined with his and he could intuit their position and condition through it.
"Now that's just petty." He said to her.
He stopped feeling their existence plus a lot of power suddenly entered his chaos Accumulation. His flame grew stronger because his actions had indirectly led to their death and they were killed by a superior nonetheless. He had forced the hand of a demon Lord to kill her subordinates. It is against the hierarchy of the demon world.
He was about to turn away when he noticed something. It was small. A seemingly unrelated death to him happened and it fed him with power. The situation made him grin.
"Would you look at that?" He said as he flew in another direction.
The demon lord's divine sense was strangely quiet but he could tell that she was fuming. The odd weather conditions were getting worse as he flew in the sky wearing a wide grin on his face.
"This has to be very good for you to want to hide it so much." He said to the silently fuming divine sense.
Beelta remained silent.
He passed the body of a dead demon on the way to his target.
"A demon's dead body should be a common sight in the abyss due to all the death that occurs but it isn't because demons aren't wasters. No one will waste such a good body full of biomass unless they are in a hurry and the body is fresh. This means that someone just killed a demon here but was in a rush. I wonder why they are in a rush?"
He said out loud to his taciturn listener.
"Still nothing to say. I can feel that I am very close." He taunted her.
"Why don't you say something? Beg me. Maybe I'll listen and spare whoever this is."
The demon lord screamed at him, "Why don't you shut up?"
"It's annoying, right? Having an incessant talker when you're having a bad time is an irritating thing but I am just paying you back for your incessant ramblings when I was just a spine with a skull. Do you remember that time when I was crushed by your surbodinates and your were talking my ears off?"
The demon lord didn't respond. She remained silent as he arrived above a high-rank demon waiting for him. The demon lord had already informed her of the arrival of doom.