This huge blade hides a secret reservoir of quicksilver (also called mercury by alchemists) that runs along the interior of the blade in a slender channel. When the blade is vertical, the mercury swiftly fills an interior bulb in the haft, but when swung, the heavy liquid flows our into the blade, making it heavier. In non-proficient hands, this shifting mass penalizes the wielder by an additional -3 penalty to attack rolls, beyond the normal nonproficiency penalty for using an exotic weapon untrained.