A Certain Unexplainable Dragon Slayer

Y/N vs Kanzaki

Y/N woke up and then went straight toward Komoe house to see how index was doing. Apparently, due to Komoe's small stature, Index was able to wear an extra bunny onesie that was laying around. Of course, Komoe wanted answers, but Y/n was determined to keep it a secret from her. Instead of coming clean, he lied and said that Index was his younger sister.

This led to Y/N begging on his hands and knees for forgiveness while Komoe lecture him about telling the truth and pointed out all the reasons why Index couldn't possibly be his younger sister. All the while, Index just stared in confusion at the situation.

After that little act, Komoe demanded that Y/N tell her the truth. However, when she also told him she intended to tell Academy City's governing board, Y/n insisted that he had to keep her out of the loop as to not get her any more involved than she needed to. In the end, Komoe decided she would give him time to decide how to answer her questions while she went out grocery shopping. Of course, she also reminded him that she may well forget about the topic, but she expected him to tell her once she got back. As she left, the student could only look on stunned at the turn of events.

"Thank God," Y/N sighed, laying down on the floor.

"She's a nice person," Index said.

"Are you talking about Komoe-Sensei?" Y/n asked.

Index merely nodded.

"We should keep her from getting further involved," Y/N pointed out.

"Yes," Index agreed, "It isn't safe for her to use any more magic."

Index went on to explain just how exactly dangerous the grimoires, and by extension magic, could be. She explained that the knowledge of the grimoires was not meant for normal humans to read. They create a sort of second world within themselves through their contents and that second world is toxic, damaging the brains of those ill prepared to take on that knowledge. The key difference being that Esper abilities rely on the personal beliefs of the individual while magic relies on the religious beliefs of a collective.

Index went on to explain that she belongs to a branch of the English Puritan Church known as Necessarius, or the Church of Necessary Evil. It was designed to conduct Anti-Magic practices through the use of magic itself. They used the very magic they fought against in order to keep it in check, hence the name.

Index went on to reveal that the reason she memorized all 103,000 grimoires was so Necessarius could understand all magic, and thus potentially fight against all magic. Y/n suggested just destroying the books so they wouldn't be used, but Index explained that it is practically impossible to destroy them. Even if the original copies were destroyed, it would be knowledge they held would survive in the minds of every sorcerer that had learned from it, whether directly or indirectly. Not to mention the originals themselves were extremely durable, so the only option was to seal them away.

"So basically, it's like there's a bomb inside your head, and some evil people want to get their hands on it," Y/N concluded, his fists shaking.

"Anyone who could use all 103,000 volumes could have the power to warp the entire world," Index whispered, sinking deeper into the blanket of the futon.

"How could you?" Y/N asked in a dangerous tone, "This is major stuff and you waited until now to tell me!"

"You were such a skeptic, I didn't think you were going to believe me," Index whined from under the blanket, "I didn't want to frighten you off. Also, I didn't want you to stop liking me."

"That's why you kept it from me! Well, I deserve better!" Y/n yelled, standing up "Church of Necessary Evil, magic robes, a whole library of evil books! Yeah, it's a crazy story and I still have a hard time buying it! But that's it. No more surprises?"