> Have this really specific thing where it’s consensual beheading when about to orgasm (I have no idea why)

Why, it's obvious: since orgasm is "little death", that naturally means death is great orgasm!

With this fetish, chances are you've already seen works by Juan Gotoh (like the image included above), but if not, you should absolutely check out their mangas "Graduation and Beheading Ceremony" and "Applicant for Death" (the latter also includes a bonus part "Guillotine Masturbation" which might be not included in some sources, so make sure not to miss it out). Those are real masterpieces, which back in the time introduced me to the world of happy casual consensual guro, and where I draw inspiration from for my own works.