10 and 16 if you’re still doing the ask game!
10. Most disliked arc? Why?
i haven't seen past season 11 so i can't really judge the later season. from what i've heard i don't like the british men of letters. and honestly, i HATE the whole legacy men of letters thing. like i get it, they're the main characters, but they come from a long line of hunters AND men of letters. also the entire men of letters bunker and society added a new layer of lore i just found unnecessary. when they started to lean more into that is when i started to lose interest and stopped watching. i just hated the premise and idea of the men of letters. there were so many cool underdeveloped potential storylines that they could've done instead.
16. If you could change anything in the show, what would you change?
i'm just going to keep this answer on the lighter side. i wish they had a least done one or two episodes in each season where the winchesters were just side characters or the episode followed the perspective of someone else (similar to bitten but not necessarily found footage).
at most i wish it had switched of main characters each season (similar to skam or that kind of show). i think there are so many cool and interesting side characters that they could've made into plotlines. i know they would never have done that for actor/contract/money reason, but i love shows like that. i would've love one season with the harveles, one following bobby and rufus, jody and donna and the wayward sisters crew, garth, rowena, elieen, cas, charlie, and even smaller characters like missouri who could've had a season devoted to development . i think that i would've given opportunities to build backstories and new plotlines without falling into the bigger gun trap the show did. the early seasons especially created a sense that the network of people was really interested and everyone had a story, but the show just followed the two brothers and you can only watch them have the same three arguments so many times. again i obviously know why they would never do that but it would've turned the show into a cool epic with the ability to explore so many different areas and plots that didn't revolve around the brothers.