I literally randomly woke up a few minutes ago with a random headcanon...
Soooo I was thinking about TMNT The Last Ronin like:
"Damn that is soooo dark and angsty.... I fucking looooove this!"
Then I thought about one of the scenes with the Ronin having a conversation with his brothers who aren't even there cuz they are dead and survivor's guilt I think (I could be remembering that wrong)
Then I thought about rbfr Sun & Moon...
"There is NO WAY those lads don't have survivor's guilt"
And as I was thinking about it, since Sun & Moon are separated bots from different locations with their other counter parts no longer around...
My headcanon is whenever either one of them are alone/by themselves (or think they are alone), start talking to themselves as if their counter part is right there but in reality they aren't.
-While Sun is trying to prepare the food for the kids in a different room, he hears his Moon counter part talking to him. And Sun is just chatting with him as if it was a normal non post apocalyptic day.
-Or Moon while on guard duty he hears his Sun counter part and just talk to him. But more listening than being chatty.
Imagine if this is how Y/N knows a little bit more about these bots through their one sided conversations to themselves.
AAAAAAAAAAAAAAAA! MY BRAIN ROT IS SO STRONG! HELP! lol
You're spot on with survivors guilt. And I loveLOVE your headcanons because I can see how they can be possible in the reality of RB&FR.
Sun can slip up expecting an answer from Moon mentally but that line has been cut. You know when you daydream scenarios of conversations with people, and they say something that doesn't fit them? That could be Sun's guilt shining through as that isn't how it goes.
Or Moon staying away from the bright lights unconsciously, since now he can walk out into daylight but not change. (Moon does not have access to his Sundrops mechanics but he can't bring himself to remove the remaining rays on his face)
These bad boys can fit to much emotional angst