During Sun and Moon's conversation (3:56-4:40), I noticed that Moon referred to Nexus as they/them multiple times. Nexus also called themselves Sun's brother. After the dream, Sun and Moon were using he/him for Nexus. So during their whole "Apology tour", as Moon referred to it, maybe they had a gender identity crisis and came out as Nonbinary or a Demi-boy? I find that really cool!
"They joined Monty in the kitchen for cooking." (4:37) THEY ARE COOKING. THEY STOPPED BEING A TECH GUY AND STARTED COOKING. OMG IMMA CRY. They are just a baby.
I noticed that they are also still pretty smart, since they helped with the TV in the beginning.
"Do you not hate me?"
"Not for any good reason. Should I? I could go back to hating you.. that was a joke." (7:06-7:25)
"I didn’t have an actual, validated reason for hating you after Solar came back. Yeah, I was irritated by how I was treated because I was compared to Moon.. and I wasn't him, but I can't blame you or anybody else for that. You post a sibling.. and got a.. clone? So I don't have a reason." (8:15-8:45)
I think that Nexus was saying that they hated Sun because of how they were treated, but them going on and doing bad things, or whatever they wanna say they did, wasn't warranted. They also added the fact that Sun did lose Moon, and he was very emotionally unstable and new back then. They are a very observant person when looking at the ep specifically.
The hug almost made me cry because Nexus isn't used to hugging, according to their statement. "I'm still really bad at this hugging thing." (8:53). Then there is Sun uttering hkw sorry he is, which is genuinely heartbreaking. I really liked that bit.
"I've been living here for like 8 months." (9:20). So this is like a LONG time after Nexus was evil. They have grown a lot of their own personality over this time, going back to the cooking and observance thing they have.
"I know I'm like your fourth brother, but you can still talk to me." (9:37-9:42) In canon, they made it very apparent that Nexus was no longer family a little after Solar died. They originally saw Solar as a best friend and then a brother, but after that they stopped seeing everyone as family as a whole. Solar never saw them as family and only as a friend. This is a very confusing duo that everyone argues over as a ship or brothers.
From my perspective, I see it as like Eclipse and Roxanne. They left that up for interpretation. This could be the same case. In canon they have no familial connection, but in this what-if they do.
Solar became part of the family after he came back,(When he first saw Terra and Cosmos on laes and in many episodes he referred to the others as siblings after that), but by that time Nexus already left. I think this what-if is like saying that they could be interpreted as brothers or as shippable characters or as past friends.
"You used dark star power."
"So did you." (12:56-13:00)
Nexus does not have the dark star stuff anymore. In Sun and Moon's conversation, Moon said that they switched their bodies, so they probably don't have it anymore. I also think that them and Cosmo would have a close relationship due to being able to cope with the dark star stuff that they both dealt with.
"The orange thing is a nose. The blue stuff is hair.. and then the brown thing has a cutout, looks like a shoe." (14:23-14:30)
Again, very observant. They noticed that stuff while I'm blind af. They also help with the whole "moving the shelf." They talked about weight, stability, height, reinforcement, and also adding Jack's weight.
I think they would be close with Monty, unlike how when they were NM. When they first came into life, they expressed that they didn't like Monty that much. Now, however, they do cooking with him, and they talk and interrupt each other casually while talking about the shelf cabinet.
"You're crying..?"
"Yeah." (16:57-17:00)
STOP. ISTG. HE CRIED. I CANNOT WITH THIS. I CAN'T EVEN ANALYZE THAT BECAUSE OF HOW GSIENEJSKDBE THIS MAKES ME.
"I thought you moved on."
"You don't move on from something like that. You accept that you couldn't do anything. I've accepted that... Something like that sticks with you... I still dream about him sometimes. Less and less recently, but it still happens, and I do miss him. I appreciate that feeling.."
I SWEAR TO GOD. I CAN'T. They are literally the "I'm starting to forget your face" MeMe. I will cry. They make me feel.