the event was organized by a group called Exiles of the Golden Age and discussed the formation of "Männerbunds." On the group's social media accounts, they describe these as “disciplined groups of men” who can rebuild our world “amidst the coming wreckage.”
So in other words, a bunch of angry leather incels came together to masturbate in a blockhut.
I too practice martial arts, and thus far haven't had the "joy" of encountering neo nazi types amongst my peers, but then again, I don't practice MMA