Wow, the wroters took the easy way out. Never ONCE explaining what the demon deal with Nero is, other than Sanctus saying that he does have the blood of Sparda in him, and that Dante had his reasons for helping. Guess they wann'a stretch it out and have us drooling more for the story in DMC5. Though Angus did say that Nero was actually a demon, though that could be him just messing with Kyrie.