Tsukimino Karma wa Akumade Boku no Pet nanoni - Vol. 1 Ch. 6

[VooXoo]

So he's not immune to Magic itself, but Ill Will? Interesting plot twist.

That's my theory, but the plot is changin so much, girl was fairly stoic in the first chapter and then became a brat right after, like if the author changed idea or was told to change her to be more dumb and funny.