The Crossover Demon [ Welcome to Demon School, Iruma-kun Fanfiction]

Prologue

Sullivan Office

Opera: We have a total of 111 new students for the school year. The representative for the freshman has already been chosen. For the staff, there is a new teacher for familiar class and few others but I'm afraid we still short on a teacher magic practice. Momonoki couldn't possibly practice magic with students alone. 

Sullivan: And there is no suitable candidates?

Opera : Unfortunately, no. Not all demons understand or perform different magic like Momonoki.

Sullivan thinks for a moment before waking to the windows behind him.

Sullivan: True but there is one demoness we both know that can perform any magic if she wanted too. A former student student of mine and a junior of yours.

Opera ears wiggles.

Opera: You mean her? She is a perfect candidate but knowing her , she'll be too busy exploring and travelling the world.

Sullivan: *Nodded.  She have been on adventure for the past few years and gained many experiences and knowledge. I think it's time for her to take a long break. She's the perfect demoness for the job.

Opera: I will contact her right away.

Deep in an underground ruin 

A woman wearing a pink adventure dress around her 20s is surrounded by a bunch of black-armoured knight wih weapons.

???: If you desire for the Moonstone, you need to defeat The Night Warriors. All of those who dare seeking the Moonstone fell into their hand.

The knight started charging towards her. The woman prepare her fighting stance and sprint towards the knight in front of her. She dodged the knight's attack and kick it center , sending it to the walls. The knight with the bow , shoot multiple enchanted arrows towards her back while the one with the sword try to cut off the head. 

The woman stare at the knight eyes? since they were wearing black helmet but they do have eyes since they charged at her, ..... You get what I mean. Her eyes turn pink and glows.

This is the lady's bloodline magic, Mesmerization.

Mesmerization, all living creatures who stare into her eyes will be charmed or paralyzed for a few seconds giving time to attack the targets.

The lady smirk and use 'Teleportation' to get behind the knights and give a powerful kick to each one of them to the air. She gather them into the same spot and gave the final blow towards the ground. The bodies hit the ground as it cracked because of the powerful impact.

She landed on her feet on top of the knights. 

??? : Does this mean I passed your test, Nyx? Not gonna lie , it was pretty easy.

Nyx is the spirit of night and have an important duty to protect one of the most powerful gemstone, The Moonstone in the lost Ruins of Moon Eclipse.