Since the MC got split into 5, there’s bound to be a sibling dynamics going on now since all five of them are bound to differ in every way. They are, after all, what the result of the MC’s despair and progressive lost of sanity and identity have become. The more they stay separated, the more they’re going to grow differently as they experience different things and form their own identities, beliefs, and opinions. But oddly enough, they’re still considered one as the ‘MC’ even though they’ve been split (perhaps through the rule of majority or something).
Regarding their ‘sibling’ hierarchy, MC 3 and MC 5 would take the eldest roles, MC 4 would be the middle child, and MC 2 and MC 1 would be the youngest, in that order. They just have that vibe, y’know?
MC 5 takes the eldest sibling role very seriously. MC 3 kind of does too, in an objective manner. Like, they wouldn’t do it out of feeling (because they’re having a hard time feeling) but rather with a sense of duty. Still, the two of them work well enough.
MC 4 likes to tease MC 2 and MC 1 a lot, so much that they even find it amusing if they can make MC 2 cry or MC 1 frustrated, as some siblings like to do. They have that older sibling privilege.
On the other hand, MC 2 and MC 1 get away with a lot of things more easily. MC 1 being a little troublemaker would just get a scolding and a slap to the wrist if they ever purposely cause trouble and MC 2 usually gets out of punishments if they cry, which they kind of do always, but anyway, younger sibling privileges.
But, as stated before, Lil’ Sal’s considered their oldest sibling so he gets the most older sibling privileges out of all.
Though, I think the MCs try to kill each other sometimes, just to show how much they hate themselves and their ‘destiny’ that they’ve been told a lot of times they can’t escape. They have an unhealthy way of coping, which is honestly understandable seeing what’s happened to them throughout all the loops.
Regardless, Lil’ Sal’s always is and always will be there for them, though. He comforts them when Father can’t (which Father usually can’t since he’s fucked off somewhere to buy milk and which Lil’ Sal is thankful for) and they appreciate him. The MCs genuinely care for and respects him.
Now that I think about it, regarding Lil’ Sal, would he be visible to others or would he not be visible as always? Since the MC split, there’s bound to be some glitches or errors with the system so maybe Lil’ Sal becomes visible to the others? Hell yeah, visible Lil’ Sal!