obviously dean and jace would get along easily, but to everyones great surprise dean and isabelle would also get along very well? because hello dean is more than jokes and drinking, hes very intelligent and likes to see isabelle work and enjoys learning about all the science stuff to further his knowledge
sam and clary? you bet. sam and luke? even better. clary would feel comfortable around sam because she has all that special stuff inside her and sam is special too, so even though his was in a bad way, he helps her through figuring out her place and that its not the powers that make you, its how you react to things. jace and sam would relate to that as well, sam would have a long talk with him about his feelings when he thought he was bad. and sam and luke would be great, luke would ask them along for a lot of his police/werewolf missions and sam would love it
cas and magnus cas and magnus they already knew each other but now that cas has dean its even better. magnus and castiel have long talks about the impending doom of their significant others mortality
training sessions between alec, jace and dean
alec losing himself to his anxiety and depression one night and doesnt want to talk to anyone because in his head its all im not enough and he’ll leave me for someone who will live forever and no one can really understand that, except dean. so dean would go into alecs room and just sit by the bed and say something like “its worth it,” and alec doesnt understand and looks up and says “what?” and dean says “i know youre tired, and i know it sucks. i know its scary to get older every damn day while he doesnt. but its worth it. because the world is a whole lot scarier when youre alone, and i took too long to realize that. im better with cas, and that makes it worth it.” and alec lets out a small tear and says “am i enough?” and dean knows that feeling all too well and he says “you always were”
lydia for sure would crush on sam lmao because sam is sooooo her type. but where dean falls easily with the shadowhunters, sam enjoys the werewolf pack very much
simon and sam also?? omg that would be so pleasant. simon would ask sam for a lot of advice, and sam would be understanding and remind simon constantly that just because hes a vampire doesnt mean hes a bad person.
jace talking to dean about his family stuff, everything inside him hurts, and dean lets him get it out and tells him that its okay to break, and that the tough guy act can only keep them going for so long
magnus would definitely convince dean to wear eyeliner one day–and then convinces castiel to put pink tips in his hair. magnus and the winchesters and castiel would probably get along the easiest, because magnus is welcoming and understanding and patient, and would call dean out on his shit making cas and sam smirk. but magnus loves them, and he and castiel kind of just stand back every once and a while, observing their two families that have merged and just think “this is what we’ve been waiting for”
After Sams accident, he had a hard time looking at people. Sam hated how people looked at /him/. Like he was a freak or they felt sorry for him. So he stared at the ground, at his feet.
Dean got him yellow shoes, told Sam about how yellow is suppose to be the color of happiness. Thought it might give Sam something to feel when he looked at the ground. Something not like shame.
Turns out they made him feel pretty special. Sam is older now and has long out grown caring what people think and looking at his feet, but he kept with the yellow shoes. So as he grew, Dean just had to keep buying him more :)