Cain The Accuser.

Beelta planned to stop the other noble families from competing with her for Aeternus while she tries to nab him. Aeternus's change to the Lord of Chaos will hamper that. The addition of the house of chaos will make Aeternus a player instead of a prize to be won.

The demon lord suddenly got an idea.

"I know what to do. Send Cain the Accuser. He is perfect for the job."

No matter how things have changed, she is still the demon lord and things are still in her court. Even if Aeternus creates more demon nobles he doesn't have the divine power to empower them. That means he can only rely on their quantity, not quality. If he relies on quantity, his soul will be burdened. A burdened soul will be more vulnerable to spiritual attacks. Cain will be able to cripple his recruitment efforts.