99.9999999999

Twelve/Nine is the first Blut-Rose created by the weaponsmith Nanbara Zuichou. It's a giant revolver with 7 bullet slots, and it is wielded by Dolly.

Because Dolly has extremely bad aim, the weapon was modified to have a blade attached to it, with the idea that the gun will have 99.9999999999% of hitting any target that is stabbed by the blade.

When the weapon is at its full power, it magically has an infinite supply of bullets, never need to be reloaded.