Today I talk about Scartho/Scab (Scar+Etho).
Scartho to me is 50% based on in-game character + fan imagination lore: Etho is someone who doesn't like to look like he needs help, doesn't actually want to be seen as "washed" or physically weak. But Scar is the only person who sees through that, he knows how it's like to want to look strong, or at least normal enough that people won't worry.
Because Scar is the same (see: disability, being undermined by others). So he won't call Etho out on it, but he will look out for Etho and sneak in ways to help that Etho can more readily accept.
Scartho works because they understand and respect each other based on personal experience/preferences that align.
The other 50% is based on more meta/"real life", in stream interactions: They have really good friendship, joke around without fear and like equals. Like Etho being a lot more willing to talk about himself around Scar because of the genuine interest shown.
I think it's because Scar is also equally willing to talk about himself/interests in exchange. And they can make more personal jokes at each other because of that (eg. Etho-specific Canadian jokes, Scar health related jokes). It's as if they're genuinely close friends who remember specific things about each other. It makes a comforting and natural atmosphere when they interact.
This is just my idea of Scartho which I enjoy and make fan works about. I can talk about them forever, but it is what I will share for now.