Dakki

Dakki is a mystical sword in the manga InuYasha that has the power to absorb yōki (yōkai powers) from them. It was created from the scale of a 'ryūjin' (dragon man). InuYasha fought against Dakki with Tessaiga, nearly draining all of its power, but in the end Tessaiga prevailed taking on Dakki's powers as well.