Ace of Spades

"Folding was never an option." -Cayde-6

This hand cannon features a black metal finish with a spade on both sides and an upside down spade outline on the grip.

Aces High

You have a +3 bonus to attack and damage rolls made with this magic weapon. Your chances to crit on this weapon is 1 better (if you would normally score a critical hit on a 19-20 this becomes 18-20).

Firefly

Ace does and extra 2d8 fire damage, additionally when you get a critical that drops an enemy to 0 hit points the enemy explodes and everyone with in 10 feet has to make a DC 17 DEX saving throw or take 8d6 fire damage, half as much on a successful save, and you also regain 1 expended charge of gambler's dodge. 

Memento Mori

Reloading after a kill gives you +10 Bonus to damage with Ace and you have advantage on attack rolls and saving throws until the end of your next turn.

Gambler's Dodge

Ace has 3 Charges for the following Property, When targeted by an attack or targeted by an effect that allows you to make a Dexterity saving throw to take only half damage, you can use your reaction to make a gambler's dodge, moving 5ft to an unoccupied space and reloading your currently equipped firearms. This movement does not trigger opportunity attacks, and you can are considered to have taken the dodge action. Until the start of your next turn, any attack rolls made against you have disadvantage if you can see the attacker, and you make Dexterity Saving Throws with advantage. Ace regains all expended Charges daily at dawn.

It’s up to you to decide whether a character has proficiency with a firearm. Characters in most D&D worlds wouldn’t have such proficiency. During their downtime, characters can use the training rules in the Player’s Handbook to acquire proficiency, assuming that they have enough ammunition to keep the weapons working while mastering their use.

Notes: Bonus: Magic, Damage: Fire, Level 20 Gunslinger, Damage, Combat, Range, Ammunition (Firearms), Reload, Sap