Satori is much more than he lets on
Satori's supposed power is Telepathy, and he also mentions that he follows the protagonists in an alleged pursuit to preserve history and totally not because it's a hobby. However, he is capable of somehow finding his way into several places to aid Yuito and Kasane, including guarded private locations like Seiran's labs, or places where telepaths Wataru and Haruka can't even reach such as BABE and Karen's Brain Field. With the potential to track people anywhere and get there via unknown means, Satori could possibly even be the one responsible for history barely changing after Karen Ret Gones himself to save the timeline, thus making Satori's claims of history preservation true.Yuito and Kaito are actually half-brothers
Given the revelation that Wakana was Kasane's foster mother who fled from Togetsu after failing to trigger the Red Strings in her and that she married Joe afterwards, it doesn't seem likely that she would be able to give birth to Kaito beforehand. It's also confirmed in at least the anime that Yuito and Kasane are the same age. Thus, it's more probable that Yuito is her actual biological son while Kaito was her stepson. However, this seems to be debunked in the anime but rather hard to say if it's considered canon that Yuito and Kaito are actual brothers.- This is actually addressed in game and the characters speculate that Kasane was put into cold sleep, like Kagero, before handed over to the Randalls
The game is a sequel to/AU of God Eater.
- The backstory of the game reveals that three thousand years ago, humanity fled the earth because it was uninhabitable and only returned when it was habitable again. The reason for it being uninhabitable is never revealed, but the original God Eater's main antagonist had a similar aim to avoid humanity being wiped out by the Devouring Apocalypse. Considering this and Togetsu speaking of an 'incorrect timeline' and wanting to go back and prevent humanity leaving Earth, as well as apparently returning to Earth on an 'Ark'(the name of the vessel designed to escape the Devouring Apocalypse), it's entirely possible Scarlet Nexus exists in an alternative universe where Director Schicksal won, and Togetsu wanted to go back in time to prevent that and set things back to the canon course. It wouldn't be the first time an alleged new universe turned out to be in the God Eater universe after all.
- This would also line up with the fact that a human can be turned into an Aragami and an Other. Perhaps the Other Particles were originally Oracle Cells that somehow mutated and were flung into space during the Moon Colony's attempts to re-terraform Earth? Plus, there's that consistent naming theme that the characters of both universes share.
The game is also a sequel to/AU of NieR: Automata
- As for The Reveal (NieR: Automata spoiler) that humanity is extinct—maybe that was a lie, or Metaphorically True as there are no living humans during the events of the game, but maybe YoRHa/Togetsu kept/recovered enough DNA samples to recreate humanity a lá Jurassic Park.
