This style of writing is incredibly annoying. Not only do we have a protagonist who pulls random superpowers out of his ass whenever the plot needs him to, he's also the classic lazy zero personality protagonist that isekai love for some reason. In Spiderman, they talk about "with great power comes great responsibility". In this one, he gets godlike powers and then chooses to do literally nothing with them. All he uses his powers for is to take more naps.
His magic creation can even make magic that effects the brain. Couldn't he cure cancer or something? Couldn't he be doing literally anything to help anyone else at all? In this chapter she asks him to save the world and also all of his classmates from middle school and he's like, "Hell no that would cut into my sister fucking time!"
Fuck this dude. He has no personality, or ambition, or morals, or ideology, or proactivity, or anything that would make him sympathetic or make him do literally anything interesting at all.