Demon king/queen is maou (魔王), not mahou-sama. It's ma for magic/demon and ou for king/ruler, while mahou 魔法 is ma for magic and hou for method/principle. Different characters, different (though kinda similar) pronunciation.
The more you know!
I get the impression from this story that even the author's bored of what he's writing. He's completely abandoned the title premise, he's creating contrived reasons to separate the protagonist from familiar characters, and he just isn't going anywhere with this.
Not sure I've seen such a fun pilot chapter stapled to such an utterly unlikeable manga. The main character is Oversummoned and Overpowered, but frankly after a few volumes of this dreck I'm the one who's Over It.