Asmodus Exile

This revolver grants a +5 bonus to attack and damage rolls made with it. While you hold it, you gain a +5 bonus to spell attack rolls.

The revolver does not require any ammunition but has 30 charges for the following properties. It regains charges after a long rest. Roll a d20. On a 20, the revolver regains 1d12 + 1 charges.

Spells Embedded In the Revolver. While holding the revolver, you can use a bonus action to expend some of its charges to release one of the following spells from it, using your spell save DC and spellcasting ability: Counterspell (3 charges), Dispel Magic (4 charges), Disintegrate  (7 charges), Contagion (5 charges), Greater Restoration (4 charges), Sunburst (6 charges). Upon a success, the target will take non-charged shot damaged without fire damage.

Countered Spells. If the target succeeds on the saving throw then the holder of the revolver must make a saving throw at the same DC as the target. At a success, nothing happens and the charge is expended. Upon a failed save, the holder must roll a 1d6 and becomes countered by one of the following spells that correspond with the number rolled. Weird (2 on roll), Feeblemind (4 on roll), Flesh to Stone (5 on roll), Hold Person (1 on roll), Finger of Death (6 on roll), Vampiric Touch (3 on roll).

You can also use an action to fire a non-charged shot that results in an additional 2d8 of fire damage but sustain half the damage inflicted -1 as recoil damage. 

Retributive Strike. You can use an action to break the staff over your knee or against a solid surface, performing a retributive strike. The revolver is destroyed and releases its remaining magic in an explosion that expands to fill an 40-foot-radius sphere centered on it.

You have a 50 percent chance to instantly travel to a random plane of existence, avoiding the explosion. If you fail to avoid the effect, you take force damage equal to 20 × the number of charges in the revolver. Every other creature in the area must make a DC 17 Dexterity saving throw. On a failed save, a creature takes an amount of damage based on how far away it is from the point of origin, as shown in the following table. On a successful save, a creature takes half as much damage.

Distance from Origin	Damage
10 ft. away or closer	15 x the number of charges in the revolver
11 to 40 ft. away	10 x the number of charges in the revolver
41 to 120 ft. away	5 x the number of charges in the revolver

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, Bonus: Spell Attacks, Advantage: Saving Throws, Damage: Fire, Artificer, Wizard, Warlock, Sorcerer , Damage, Control, Detection, Combat, Deception, Warding, Range, Ammunition (Firearms), Reload, Sap