Chizuru is the grim reaper
Chizuru is confirmed to not have been part of the original cast, yet she seems to be on friendly terms with everyone. It's even stated that no one knows WHEN exactly she died, or what her deal is. There's a very real possibility that Chizuru is the one running things there, which also explains how her Berserk Button is canon breaks. She knows how things went because she was WATCHING.
SHSL Wild Card is actually how things went...
According to Enoshima.
Following up on the theory of Chizuru being a Shinigami, she'd likely be able to account for ALL versions of the timeline, from everyone's point of view. Look closer at Raven's talent- It's literally everything. She's the best at everything, and who was actually best at everything in Canon? Izuru Kamukura. Who had a hand in Kamukura's creation? Enoshima.
Following up on this, Word of God confirms that three of her Danganronpa fanfictions are linked. Assuming this one is linked to the Despair Infestation rewrite, it's very possible that artificial humans are possible in this universe. Which means that Raven is almost certainly one, albeit she's more of a Humanoid Abomination than anything. Junko made Raven, and Chizuru is trying to erase the evidence of this.