Two ideas and I don't think I have time today to write either of them
1. Video essayist trying to summarize the career of a local supervillain slowly realizes they're Tumblr mutuals.
2. Polycule that runs on highlander "there can be only one" rules but with collars instead of beheading
In what sense do you mean the second one? Because this can read as both "only one can collar everyone" or "only one can be collared by/for everyone" and the way things are going I'm plummeting towards the second one very fast
No I mean they play The Game that the Highlanders play, but with D/s instead of murder.
It starts with everyone a dominant. Their goal is to be the last dominant standing: this is The Prize.
The way you win is by collaring other dominants. This makes them into a submissive.
Submissives can't collar people, but they add their support to their dominants. So each dominant and their personal set of submissives have to try to collar other dominants, through persuasion or force, until there is only one neck without a collar, ruling over a polycule of their submissives.
(and when you collar a dominant, you swap all their submissive's collars for your collar, as you take their "power" when you defeat them)
I can't believe I wrote all this without saying the key word "highlandercule".