WMG / Devilman

Akira is The Antichrist.

Devilman Grimoire is the latest incarnation of the Devilman universe.
The Devilman universe has gone through many cosmic reboots. First was the world of the original Devilman manga. After it was destroyed, it was rebooted into the world of Violence Jack. This was then rebooted into the world of Devilman Lady. This was then followed by the world of Shin Violence Jack. And then it was rebooted yet again, this time into the world of Devilman Grimoire, which seems to combine elements of all the previous incarnations (so far featuring characters from both the original manga as well as Devilman Lady) as well as elements from the 1970s anime series. In this sense it is similar to Stephen King's The Dark Tower series, where time also works in a cyclical pattern. The fact that Grimoire is set in the present day, with characters who originally existed in the 1970s (Devilman) or early 2000s (Devilman Lady), also bears a resemblance to the History Monks of Discworld and how history is manipulated by them.

  • And it will be the last. Either the main characters will prevent another reboot or God will realize his error and feels he's punished Satan long enough.
  • And it has since been revealed that Devilman Saga will actually be the final incarnation of the Devilman universe.

Ryo's story of the professor's fate was an inversion of what actually happened.

The end of the manga makes it very clear that Professor Asuka never did any research on demons, which calls into question if any of what Ryo said about his father was true. So what really happened to the professor? It's possible that the demons out and out killed him after Satan assumed Ryo's identity for the sake of The Masquerade and the backstory was another one of Psycho Jenny's implanted memories, but there's no reason why Psycho Jenny couldn't have just hypnotized him like she did Satan. Maybe the Broad Strokes of the story took place, but Ryo's explanation inverted the motivation behind the professor's actions.

Going from this, Professor Asuka did become a devilman, but:
  • Instead of killing the family dog out of demonic blood-lust, he killed it because it had been taken over by a demon and tried to kill him.
  • Instead of the demon inside the professor trying to kill Ryo, it was the professor himself taking action after realizing that "Ryo" was not really Ryo (possibly learned from the memories of the demon that possessed him). Rather than his human side taking over and committing suicide to protect Ryo, it was the demon sacrificing itself and its host to protect Lord Satan.

Ryo was not consciously aware of his true self until much later, so he would not have known any of this and was only going based on what he observed.

In at least one timeline, Miki and Siren became a Devilman team like Akira and Amon

Because at some point, Siren's going to realize the obvious win-win of becoming one with Miki would allow her to be with Amon, keep Miki alive, and possibly avert the rebooting nature of the universe/

God is dying

Satan says that he "won" when he fought against God and then froze himself. Why would he decide to freeze ? Because he landed a killing blow on God, but needed to wait until God ended "bleeding out". God's actions during the bombing are actually his final death and the angels coming to Satan are seeking revenge for the death of their father.
http://tvtropes.org/pmwiki/pmwiki.php/WMG/DevilMan