The Spark Of Chaos.

His voice sounded like the peals of judgement. "I told you, if you're useless to me, you will die. Now I'll give you a chance. You either succeed or you die trying."

He created a ball of chaos in his hands. It was like an orb created with a dark exterior material but containing a bright white substance shining from within. He understands it to be the chaos spark, a feature under his Oath of the Chaos Lord's ability. It can be given to anyone but it can be refused if that person is unwilling to be his subordinate. To receive it, the demon must swear an oath of allegiance to him.

He asked her. "Will you serve me?"

The snake spoke as it saw the dangerous looking ball that Aeternus is offering it. "Xander will do anything to grow stronger. Anything at all."

"Then take it. Either you evolve and become of use to me or you die."

He let the ball float to the demonic beast and she swallowed it. He would have killed her if she refused.