Sparring weapons have some really fun and mobile stances but aren’t used much except for Hirudo lifesteal (and that doesn’t scale so well nowadays). They could benefit from an aoe increase (i.e. hitting out waves, phantom punches/kicks to either side), a way to translate their mobility into damage (i.e. parkour speed on kill, damage based on parkour distance) or unique scaling gimmicks that fit their power fantasy (i.e. armor/overguard-shattering punches).