Curate, connect, and discover
Wilbur didn't have abusive as much as he did neglectful parents, so when Tommy (5) and Technoblade (10) paid his house a visit, they took one look around and decided "yup he's ours now".
Tommy cried a lot as a kid. Not necessarily out of sadness, that was just how he reacted to very emotional situations. When he was older, it turned to yelling because he didn't like the pity he got before.
Tommy didn't bother to make his own views on government, but looked at Wilbur getting into it and went "no king <3".
He went with Techno's ideology, "I seriously couldn't give a fuck as long as it isn't bothering me".
Niki was found as a 12 year old in the lake, and was the only kid Phil needed no persuading to keep. She was a sweetheart.
Ranboo is a jerk but. Different, depending on who he's with. He's a lovable asshole with Bench Trio, but just an actual jerk with everyone else. He has favorites.
Tubbo and Ranboo act like they hate each other, so it was a surprise to everyone when they announced they were (platonically) married.
Scott crash-landed from the stars onto the SMP when he was younger, and claimed homophobia whenever Phil tried to get him to leave. So he stayed.
Phil's the resident father figure and canon 911 so he gets no sleep and needs to be paid more. He loves them though.
Fundy’s just a random kid Wilbur picked off the streets, he's barely younger than him. Wilbur refused to let him go.
Technoblade spent a lot of his childhood looking after Tommy, so once Tommy had friends and family that could take care of him, and he was old enough, Techno left to wander the world.
Wilbur flickers from invisible to solid when he's agitated/sad, so people take objects from him when he's feeling intense emotion.
Niki's like Ranboo's big sister, and tends to mediate all the fights he gets himself into. (A lot of them). She's the only reason he's on speaking terms with like half the server.
Ranboo and Tommy met before they met Tubbo, on one of Ranboo's few trips to the Overworld he was allowed when he was younger. They kept in touch through letters and sneaking out.
Ranboo's a prince, but ran away to live his own life. He didn't know many survival skills, and refuses to accept help.
Technoblade and Tommy were attached at the hip when they were younger, and Wilbur got jealous sometimes.
Techno insisted on Tommy being named Theseus, just because he loved the name. He calls Wil Icarus. He refuses to tell him why.
Tommy introduced Tubbo and Ranboo, it was hatred at first sight <3 (then they got married).
Ranboo's of the firm belief that money can buy happiness, actually. He throws expensive shit at his friends to cheer them up.
Charlie is God. That's it. That's the headcanon.
Ranboo looks up to Phil a lot, despite how he acts. He desperately wants to make the best father figure he's had proud.