Mailbreaker

Mailbreaker is a type of dagger used by the assassins that are members of the Eight Fingers organization.

Description
Mailbreaker is a weapon originating from the New World. They are used by Eight Fingers's assassins to silently kill off Sebas Tian.

Appearance
Brain Unglaus noted that these weapons look like a double-edge sword in the shape of a dagger.

Abilities
There were reservoirs carved into the blades of their weapons, and said reservoirs reflected the oily glow of a dangerous liquid.