Great World-Shaker

weapon name: Great World-Shaker
description: A massive, two-handed sword made of an extremely hard carbide steel. It's lustreless blade is five feet long, four inches wide and an inch thick, of the western style of greatsword. The hilt is plain, black, with a T-shaped handguard. It looks as if it's seen a lot of use, with scuffs and nicks all along the blade.
weapon special abilities: The entire blade of the sword is actually hollow, filled tiny with mercury-filled beads. This causes the weight of the sword to shift unpredictably as it's swung, making it very difficult to use without practice. However, when the blade strikes, it does so with incredible momentum which can split rocks easily and damage steel. It also reverberates on impact, the vibrations further damaging objects and disorienting living enemies.
history: The sword was a custom order placed by a mad pirate captain. He paid his commission up front, requesting a sword that would "shake the earth itself" when it struck. He died in battle before picking up the sword, so it was sold to the marines at the highest bidder. Nobody could make good use of it until Kalamity came along.

Approved.