Still no explanation as to why Greenbull's blade
- Is black in color
- Has a hamon-shaped white line in the middle
- Is much thinner than the handle
- Is piercing through his pants
Which is all heavily indicative of a black blade rather than a black sheath, since a sheath is of the same width as the handle (if not bigger), doesn't have a reflection shaped like a wave/hamon and isn't piercing through the pants, but is attached to the hip.
The answers to these question remain unsolved.