Nasu

"I get it. I'll fight as if I were naked." Rein said with an honest face.

Which Is So Badass That Every Word Needs To Be In Capital Letters.

Would make sense if it had been 15 years before he reincarnated. But as soon he came to this world and recognized it he would have recalled everything he could remember, significantly boosting his ability to recollect things later.

"As a token of our gratitude we allow you to continue serving as our guard."

Warn them so they have a chance to take hostages. Good choice. Otherwise where is the challenge?

Well, of course. Whenever you join a group you need to build up relationships. They don't come automatically just because you initially became part of the group.

I could fall for this kind of girl :D

"Hogwarts: From Luna's family to god" by Rui_Chen_3499. You may find it on FanMTL

Wasn't that the end of the school year exam exercise?

Expected when you involve yourself in plots without disguise.