The Commander's Blade
This sword was crafted by the citizens of Lolien as a thanks to Caraconne Lashi for her heroics in the The Witch Wars. While you are attuned to this weapon, you may cast the spell Command as a bonus action immediately after you strike a target with the blade. The target of the spell must be the creature you struck. The DC is equal to 8 + your proficiency bonus + your CHA modifier.