An Immortal in Another World: Reborn as a Baby, I'm Already Invincible

Protagonist: "For the sake of all living beings, what does it matter if I become a demon god?!"

Demon King: "Lord Demon God, your sister is in my hands. Even if you kill me, I'll take your sister down with me! Why not let me go?"

Protagonist's sister: "My countless fellow cultivators have all given their lives for the sake of all living beings. If the demons aren't wiped out, the world will be plunged into misery!" With that, she destroyed her divine core and her soul was obliterated!

Protagonist: He crushes his sister's divine core in one hand and uses the "Otherworld Reincarnation Technique!"...

This novel and its characters are entirely fictional. Any resemblance to real people or events is purely coincidental. Do not imitate.