User blog comment:SpookyBoogie27/Light Novel Spoilers/@comment-23853100-20140210121845/@comment-1359322-20140210132828

With Rizevim and the current Four Great Satans around, i'd say reviving the True Lucifer is kinda meaningless anymore. Not sure about the Four Horseman of the Apocalypse but i don't think they'll appear at all. Remember Sairaorg's Knight, Beruka Furcas. He is like a living reference to those four. The Four Horsemen rides Pale Horses. Beruka also rides a Pale Horse. Those four are probably dead in the previous war too.

Anyway back to the original topic, i think Ishibumi could focus more on the Greek and Hindu myths. Those two are already placed in the plot but hasn't been explored yet. It wouldn't be a bad decision to focus on those two.