💪 Belted Wrestler
Tight-belting is a very common preventive measure against evil spirits that is widely practiced even by simple peasants. Some dangerous areas like dark woods, deserts and swamps have posters along the main roads, explicitly encouraging people to fasten their belts as much as possible before entering.
Ninjas take that precaution to the extremes, some elites able to rope themselves to the backbone during their missions thanks to special herbs and medicine. This extreme ability is normally trained through daily practice of belted wrestling, nothing like extreme pressure on the waist as the wrestlers force each other's strong and flexible bodies into all kinds of difficult positions.
Of course it's not exclusively wrestling and the ways to improve protection skills can be quite varied: belted swimming, belted yoga, belted bellydancing and even tight-belted tightrope walking. Everything, as long as it has 'belted' in it, is good in the difficult times when the evil is spreading...