maaaaan this is so hard to answer. i'm such a "yes, and" kind of person usually, so you can honestly pitch me almost any headcanon and my reaction will be "okay i can see it!!!" even if it's not something i'm into.

i'm sure that's not a satisfying answer, but it is the Way That I Am!

instead i'll share something that i did already like but have gotten more into than i expected: sanzo! when i started reading zsz fic, it was largely zosan or switch fics with a couple sanzo fics sprinkled throughout. since some of my early fandom friends were sanzo mains, a lot of the headcanons and prompts that i was exposed to early on ended up being sanzo-focused as well. it's still great and i love it, but it's not something i think i expected to be so present in so many of my fics.