I started this after seeing the AC theories on TVTropes.
Is it possible, that Blaze is the son of the Demon Lord? I have a few points here:
1. The cutscene after ACZ's The Stage of Apocalypse shows a man and a child watching one of the nuclear detonations. Since you only see their silhouetted figures and not their faces, the man is possible Cipher and the little boy who's hand he's holding can either be his biological or adopted son Blaze.
As Quinn said, he was in the air at the time, so that's not possible. Also, even if it were possible, taking your son to see a ground level nuclear explosion with radiation and fallout would be maybe the worst parenting ever.
2. If Strangereal's timeline suggest that the little boy could possibly be 5, than 15 years later he'd be 20 and eligible to become a rookie OADF pilot.
Something being possible doesn't make it true.
3. This may also explain how Blaze is such a freakin' beast on the battlefield, pretty much striking down all opposition.
That's par for the course in Strangereal.
4. AC04 and Operation Katina might have been Cipher's last war, since I think he was in his late 20's during the Belkan War. If this is the case, than he would have been in his very late 30's by the time the Usean Continental War happened. Operation Katina called Cipher, now Mobius One, back into the cockpit possibly for the last time. After that, Cipher possibly retired and went off the grid, possibly to avoid retribution from his enemies.
This has nothing to do with whether or not Blaze is Cipher's son.
What do you guys think? Is Blaze potentially Cipher's son?
1. A game creator wouldn't do something like that unless there were a narrative reason, and there is none. So even if it's possible, there's no reason to suppose it true.
2. Of your four points, three of them have anything to do with whether or not Cipher is Blaze's son, the first one is outright wrong, and the other two are ancillary to the first.
Not to mention, it's an empty theory. Even if it were true, it would have no significance for how we'd interpret the game. Is Blaze an AI? Is Blaze a clone of Nagase's father? It doesn't matter, because who Blaze is never figures in the story. This is a problem common to the great bulk of TVTropes thinking, but it's especially prevalent in WMG pages.
...well, I suppose if Blaze were a clone of Nagase's father, that'd put her wanting to protect him in a new light, but that's beside the point.
Next time you're in class, ask your English/Lit teacher more about what makes a valid reading of a piece of media. They'll probably explain some of this better than me, and I'm sure they'd love to hear someone curious about the subject.