"Like a flash of lightning, the idea came to my mind"- Varis Laucian

The revolver body and barrel are shaped like a white fox laying down with its mouth open. The hammer of this revolver is the tail of the fox, and the handle is bolt of lighting that is frozen in time, still humming and faintly glowing, and the trigger is made of the same lighting as the handle.

The head of the fox is adorned with a black lightning symbol, and its eyes as well as mouth are normally closed with the lightning losing its hum. However when fired the mouth of the fox opens as if to bite and lightning arcs between its teeth coating the bullet that is launched through it, the eyes of the fox also open in a glare to reveal that they are balls of lightning. When When fired the lightning bolt used the handle begins to pulsate more and more after each successful shot, and in tune with this the foxes fur raises and crackles with electricity. 

The bullets fired from this weapon become akin to small bolts of lightning as they travel through the barrel and get fully coated in electricity as they pass out of the mouth. When these lightning bullets hit a target and are lodged within them they begin to emit harmless crackles of electricity. However when the mouth of the fox snaps shut after these bullets hit the target, the previously harmless bullets begin to lance out electricity, then damaging and stunning the target. 

Lightning-Infused Bullets. This weapon has a +3 bonus to attack rolls, and deals an additional 1d8 lightning damage on a hit.

Overload. Once per turn a creature hit by this weapon must make a DC (13 + 2 per successful hit that round) Constitution Saving Throw on a failed save it takes 1d12 lightning damage per hit and is stunned until the start of the wielder's next turn. On a successful save the creature is not stunned and takes half as much damage.

Reload. This weapon can be used 6 times before you must spend 1 attack or 1 action to reload. You must have one free hand to reload a firearm.

Misfire. Whenever you make an attack roll with a firearm, and the dice roll is equal to or lower than 1, the weapon misfires. The attack misses, and the weapon cannot be used again until you spend an action to try and repair it. To repair your firearm, you must make a successful Tinker’s Tools check (DC equal to 8 + misfire score). If your check fails, the weapon is broken and must be mended out of combat at a quarter of the cost of the firearm. Creatures who use a firearm without being proficient increase the weapon’s misfire score by 1.

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: Ranged Attacks, Damage: Lightning, Damage, Combat, Range, Ammunition (Firearms), Reload, Sap