HI ANON!! 💖 this is honestly a tough question for me because i'm a rare pair enjoyer, as well as a p0ly enjoyer. but with that being said, i have some favorite pairings so i'll list the ones that come to mind and whether i've written them before:
5kz:
- hyvnsvng (written several times, the most out of all 5kz pairings)
- sevngn/sevngyng (also written a couple times and have a long wip for them!!)
- bnsvng (written once but have a couple wips)
- 3r4ch (only wip so far)
- bnchn (only wip so far)
- mnsvng (written once and have a couple wips)
- sevngbn (written once and have a wip)
- hyvnmnsvng / sevngnbn (my favorite ot3s that i REALLY want to write at some point)
- other jsvng pairings (haven't written yet but would like to take a stab at the rest!)
8tz
- yvnsng (written once and have a wip for them)
- h0h0ng (have a wip but i'm DY!NG to write them)
- 2h0 (written once!!)
- jngsng (have a wip for them...)
- mns4ng (have a wip for them ohoho)
- yvng!s4ng / 2h0s4ng (couple of my fave ot3's, would love to write)
- pretty much all yvnh0 pairings, would like to take a stab at any i haven't attempted yet!
- p0lytz (hinted at them in the yvnsng but would have fun writing an actual fic for them because there are so many good combos! exquisite rare pairs just like 5kz)
str4ytz:
- b!njccng (have a wip for them actually heheh)
- hcngsvng / hcngchn / 3r4chjccng (would have fun with any of these tbh!!)
- ye0b!n / je0ngye0 (been thinking about ye0 and cb or imie since kngdm honestly)
- yvnchnl!x / yvnsvng (once again, i just think that yvnh0 and jsvng deserve all the kisses they can get!)
- both groups p0ly and combined because i can
xkrs:
- 2prk (written once and NEEEEEED to write them again UGH)
- hvnjae (wrote as a side pairing but would live to give them their own fic)
- wccjvngz and/or with jnmn (they're so silly/cute and i'd love to write them with and without jnmn!)
- yejvn / 2prkjvn (fave yvjvn pairings that would be fun to explore)
- svsik (they are just so kajdfj i would have fun writing them too!!)
- for them, would probably be most interested in writing different jnmn OR seevn pairings, i haven't read enough to decide yet
but i think that's everything for now... i stuck with just kp0p because i've had SO many favorite pairings over the years oopsie. sorry if this was more than you were looking for 😭 but also thank you so much for asking, ily lots for sending something in!!! 💖💖

ohhhh this is an interesting question, anon!!! something similar to a time-travel situation? because if so, those au's are super fascinating! i think they're challenging to plan and write but in terms of reading, they're so rewarding when they're executed well! and in terms of a related au, i'd love to see a sci-fi au similar to !nterstellar where a team of people have to save a group stranded on a planet far enough away that time becomes a crucial factor. the difference between earth time and this far away planet. could be 8tz, 5kz or xkrs honestly and i'd eat it right up!! also another interesting au would be a couple members of the group going back in time to fix a historical event but getting captured because they're not supposed to be doing that oopsie! and it requires a rescue mission! similar to either the vmbrella academv, l0ki or the novel "fvture of another timeline." thanks for picking my brain about this and i hope this answer satisfied you?? feel free to let me know if i was way off base in my thinking hahah 💖

FERNNNN bless u for sending things, truly! but lets see library au... thinking a small town public library with... honestly? secngscng. hwa took the job as a librarian a few years ago. he grew up in that town so he felt compelled to come back. to try and make a difference in the community. but not much happens around there. UNTIL his longtime academic rival comes back into town. the ridiculously book smart ye0 who attended an ivy league college up north and hasn't returned since high school graduation. but now he's back and he won't stop coming by the library. hwa is convinced ys only does it to fuck with him. especially because they often end up bickering, rehashing the past, whenever ys visits (not that hwa is the person always starting things noooo) and hwa is starting to get fed up. he finally confronts ys about why he's there and ys admits that other than their upcoming high school reunion, he missed home. that even if he doesn't stay permanently, he needed to come back and see if this was the place he wanted to stay. and he even goes so far as to say hwa is the reason he's having trouble making his decision (but won't elaborate, he just flees the library). they meet again at the reunioin a week later and things come to a head. first they're fighting over a drinking game, then over what happened senior year of high school, and next thing you know, they're, well. "going at it" in the bathroom of some poor old classmate's house. and in my mind, they have a happy ending. whether that be long-distance relationship or ye0 staying. not sure what would be the best but! i hope you enjoyed all this rambling and ty for getting my brain juices flowing 💖