Split Sword (5e Equipment)
From D&D Wiki
Martial Melee Weapons
The Split Sword is a pole arm with a blade at either end. The shape of the blade can vary depending on where it was made. Common shapes include scimitars or straight swords. It can be taken apart at the hilt and wielded as two separate weapons.
When you take the Attack action and attack with the Split Sword, you can use a bonus action to make another attack with it. If this attack hits, you deal 1d6 slashing damage. Add disadvantage to the attack roll, and you do not add your ability modifier as well. You don't add your ability modifier to the damage of the bonus attack, unless that modifier is negative.
As a bonus action, take the weapon apart by the hilt and dual wield the two bladed. Each attack deals 2d4 slashing damage. This can only be used if you have not attacked with the sword already.