Need some help in remembering a mnga I had red

[Warmanga]

What I remember of the manga is that the mc is human and his parents are employed by demons
Mc becomes a demon lord candidate by waking up next to a card and his parents send him to the demon school where he gets acquainted with the strongest demon whose family used to serve the demon lord of his card previously.....

 

[schlo]

@Warmanga this one maybe, https://mangadex.org/title/47193/maou-gakuen-no-hangyakusha

Just an fyi, red is a color, read is the word you were looking for.

 

[Warmanga]

Thanks ..... It was a typo