Bout

Weapon (pistol), rare (requires attunement)

Bullet and blade; all one needs for a proper duel. You gain a +1 bonus to attack and damage rolls made with this magic weapon. This firearm counts as a shortsword for the purposes of melee weapon attacks. 

Point-Blank. When you hit a creature with a melee attack using this weapon, you can immediately make a ranged attack with this weapon against the same creature as a bonus action or by using one of your extra attacks. You make this attack with advantage, ignoring the disadvantage caused by being within 5 feet of the target.

Declaration. You can use your bonus action to summon a spectral glove in an open hand and throw it to a creature within 30 feet of you to challenge the creature to a fair duel. The creature must be able to see you. The target must make a Wisdom saving throw (DC 8 + your proficiency bonus + your Charisma modifier) or become provoked by you. Each turn, the provoked creature must use its action to attack you. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. 

This property ends if you or the provoked creature deal damage to or are dealt damage by a creature uninvolved in the duel, as it has sullied the conditions of fair play. If the creature cannot attack you on its turn, the effect ends.

Once you use this property, it can't be used again until you finish a short or long rest. 

On the field of battle, there is little time to worry for one's honor and fair fighting...

…so sayeth the weak of spirit and black of soul! Dire circumstances are no excuse for forgetting one's manners and sense of propriety. Grasp thine blade firmly in hand, and educate these brutes in the way of proper gentlemanly conduct!

Pierre the Proper, before being assaulted by 7 bandits and a passerby who joined in for fun

Swordtember Prompt: Duel