User with this ability either is or can transform into a Ippon Datara, one-legged mountain spirit with appearance of either human-like or a huge pillar. Regardless they have a single eye on like a Cyclops, a massive body and only one leg. Normally they don't show themselves to humans and let only their presence be felt, but at certain times they may become aggressive. According to some stories, an Ippon Datara is a very skillful blacksmith, giving them two possible origins: