How Not To Summon A Demon Lord Episode 7: Overwriting = Bad but Command = Good?

The Prince returns and Shera follows him leaving one depressed Demon Lord. However, Rem and Alicia get Diablo back on his feet and then it is time for a showdown between the Prince’s ability to overwrite Shera’s will with Diablo’s ability to command her to tell the truth as his slave. Wait? Who was supposed to  be the good guy here?