Whirlwind Bolas

The metal weights of this magic weapon are inscribed with spiraling sigils of the wind. When you throw this bolas at a creature, the DC for the weapon's Strength saving throw is 15 instead of 10. If a creature deals slashing damage to the bolas to free itself, the bolas can't be used to reduce a creature's speed again until the next dawn, when it knits itself back together.