The universe is based on Marvel and the DC Animated UniverseGiven how its a crossover of japanese superheroes come together with new adventures its not surprising.
Sailor Moon is the universe's equivalent of SupermanI know, even though Goku is a Superman expy, Sailor Moon is one since some of the original characters are base on Darkseid and Lex Luthor.
The Demons of Makai/Meikai have relations to Onimusha
Pairing theoryIn a yet-to-be-written installment, Rika Nonaka will get together with not Takato Matsuki, but Zoe Orimoto. Because as near as I can tell, it honestly seems to be what the author's planning, crack-shippy though it is.
Dawn of Chaos pays a big tribute to Dissidia Final FantasyThink about it, an ultimate showdown between the forces of order and discord.
The Prophet/Millenniummonis the same being in two timelines.Due to the recent announcement in Chap 30 of Wrath of Pharaohmon Redux with two timelines (one is WoP original, and the other is the main one that follows WoP Redux), one reader wonders if there is only ONE Prophet existing (to further Harbingermon's warning in Chapter 55 of Dawn of Chaos).
Himura Tsubasa and Phillipe Sagara are the Elric Brothers.Himura's the hotheaded one, while Phillipe is the shy one.
Either Kaiser Ghidorah or Gamera is Shao Kahn.Because he wants to become the Elder God once he gets the Romulus Source.
The mysterious Ora Guardians might be the Guardians of the Universe from Green Lantern.