It is difficult to choose the most impressive thing I saw at BiM 3 - there was gravity defying handbalancing, hyperbolic Cyr wheel, Karate, and world-class breakdancing. The thing that wins though is the terrifying sound the Kung Fu chain whip makes when spinning at full speed. Honestly it sounds like a jet turbine. I am not sure how effective it is as an offensive weapon, but the sound of it is enough to scare the enemy away. It is hard to appreciate how loud it is in real life but you can get a sense from this video.