Plan

She is promptly sent to a large humid cavern. The only light comes from large pillars of fire coming from the ground. Nia looks up to see her entire school within the vast cavern. Thousands of confused and tired students staring wide eyed at each other. No one dared to speak. She looked left and right multiple times to find some school faculty, but none were in sight.

A loud booming voice echoes within the terrifying environment, "You humans didn't even protect your kin? It will be quite easy to vanquish the Chosen one now. Pathetic.... I'm curious if one of you could truly slay me. As long as I kill you now you won't come to bite me back later." An ear bleeding laugh howls throughout the cave.

Nia peers forward through the scared mass students to see a large man floating in the air. With horns that curl like vines and a demeanor of power and vengeance. A purple gaze that seems to see through existence itself. A being beyond logic. Unlike prior myths and legends, the Demon Lord was actually handsome. Rivaling murals of gods often found within holy sites. Nothing like the Eldritch being written throughout time.

The....man...? In front of her started speaking again, "It seems your superiors already reacted... Well I'll be seeing you again soon. I can't believe someone is capable of tracing my teleportation spell... and a human nonetheless. I must be getting rusty..." He muttered.

"He has quite the ego," thought the lost girl. The Demon Lord did indeed think of himself as a godly being. Humans have progressed by leaps and bounds since the last altercation with him. Whilst recovering his strength he overlooked this fact due to his hatred towards humanity. Or in his words, "Backstabbing Bastards." In his eyes he thought it was ironic to call him a demon, when they're devils as well.

Suddenly every student started to have a slight glow. Nia looks around and stares at her hands. For some reason she doesn't seem to have any glow. In a flicker of light every student in the cavern disappeared. Every student except Nia Romera.

The Demon Lord glares at Nia and remarks, "Their callback spell must've used your unique mana patterns to identify who to send back. Hahaha! You are too weak! To not even get picked up from that spell... I truly pity you. I won't kill you yet. You could be very entertaining." A booming laugh rang through her ears, "Who knows, you might be fun, but I'd rather not get attached to a human again."

His words looped around Nia's head over and over. Then she remembered a lesson she got from her history class earlier in the year. It's believed that the demon lord grew to hate humanity due to being betrayed by a human lover.

This gave Nia an idea that rivaled all the idiotic decisions throughout history. She admits she is not strong enough to slay the Demon Lord.

This doesn't mean she cannot defeat him. The Demon Lord seems to seek vengeance on humanity due to a gaping hole within his heart. Maybe the true way to win is to fill that hole. She already knew that her beauty rivaled ancient goddesses of youth and beauty. She was told this all throughout her life. Who said a Demon can't love a goddess? She began creating a plan to use the Demon Lord's deep hole within to her advantage. Maybe she could make the Demon Lord love again.