Demon eater blades

Demon eater blades are the swords used by Shinigami, and much like the ones in Japanese mythology they have a living spirit inside of them and can change forms, in some cases these can be manifested into physical beings, though this does reduce the wielders power slightly, it does give them another person to help them with in battle. They have two other forms than their normal Katana forms :Ken no katachi daiichi (or simply daiichi) and Ken no katachi byō (or Byo). These form vary in size, shape and power depending on the user. The spirits inside of the blades are considered as a type of nephilim, this is because they themselves have no particular alignment to demons nor angles.