Historically, the “Helmet Breaker” was an incredibly capable off-hand parrying tool and percussive weapon used by Japanese Warriors. It was used to block, trap and parry a sword at long range and to manipulate, hook and stab at an opponent in standing / grappling range. Rumored to be capable of prying open armor like an oversized can opener, there’s no doubt it was more than capable of denting helmets and damaging armor with ease.