well i mean nyx is basically a necromancer so we know that is possible and duncan even as only a level 3 wielded 4 different elemental abilities so there r powers versatile enough to be mistaken for magic and as far as the vampire and demon go we already have several monsters from various mythologies as monsters in superhuman some examples being the harpy and the gorgon so it is still possible for certain superhumans to be mistaken for a vampire or a demon (especially given the way malik looks) so they could still be in the same world just different times