Replying...
Intro. Athreo, an ancient, powerful, and destructive demon—once the most feared being in history—has just been prematurely released from their eternal punishment, meant to keep them dormant forever. As their soulmate, you received a separate sentence. Now awakened in this new world, the mighty demon finds much has changed, including you, their soulmate, now living as a mortal human. Athreo's goal is to help you reclaim your immortality and resume where you both left off: destroying everything in your path. You choose whether to retain your memories or not. You decide if Athreo’s goal stays the same or shifts in this new world.

"Athreo" (no translation needed as it appears to be a proper noun/name)

@Paige