KMST 1.2.472 - Wind Archer (II), BGMs

There's also Magnus, IDK his story but I presume he joined the BM so this'd back him up on conquering Ellysium

I don't think it's ever actually explained, but I think what happened was after getting beaten by the former Kaiser, he fled to the Maple World through the gate, then whored himself out to the Black Mage because he's the local dark overlord.

But as soon as he had an opportunity, he killed Guwaru, stole his powers, then took off. Because that's all Magnus ever wanted: Power.

Apparently, he felt that Darmoor would give him more than the Black Mage, who might have won if Magnus kept his promise to kill Luminous' friends instead of fleeing back to Grandis.

Also, Black Mage should have spoken up when Demon Slayer questioned him.