Mephistopheles, as a demon noble with a strong hatred for angels, was very pro-war leading up to the Armageddon. Though RAD does not exist in this timeline, Mephistopheles is in charge of a professional newspaper, which he uses to publish dozens of propaganda pieces encouraging the war effort, ranging from incendiary papers about the angels to blatant calls for war.
However, eventually the Armageddon hit too close to home. As the war broke out, Mephistopheles lost his brother to the freezing cold. The death of his brother sent him spiraling, and now he’s wondering what to believe. He’s gone on a search for Diavolo, wanting to mend their relationship for comfort and closure.