....
Okay, yeah, it's a generic villain du jour. Hell, even his name is "Vilan". But I guess that's just the influence of the Japanese Noh Theater. No shit, the characters in those plays are literally named after the archetypes they portray.
That said, even if it is a generic plot, I feel like they should have led off with this at the beginning. You know, have this evil god show up and offer Vilan PHENOMINAL COSMIC POWAH (iiiiity bitty living space) and go from there, treating the developments on the Demon's side as a "B" Plot while the "A" Plot carries on... That is, until the two plots finally collide and then shit really kicks into high-gear.