Arcano

This elegant arcane rifle can fire bolts of arcane energy when fired, due to its installed arcane core The rifle's arcane core has 3 charges. You can expend 1 charge when taking the Attack action to make all of the attacks you make as part of that action deal Force damage instead of piercing.

Additionally, you can expend 1 charge when you make an attack to empower the shot being fired. If you successfully hit the target, the bullet continues traveling through their body in a straight line for 20 feet. If another creature is struck by the bullet, and the initial attack roll exceeds their AC, they take the same amount and type of damage that the first target took.

You can also expend all 3 charges to overload the rifles arcane core. The next attack you make will be a critical hit on a roll of 17-20 on the d20, but will also misfire on a roll of 1-5 on the d20. If the weapon misfires it can't fire again until you take an Action to attempt to repair it by making a DC 10 Intelligence (Arcana) check.

Once the arcane core's charges are depleted, they can be fully recharged by infusing them with a spell slot of 2nd level or higher as a part of a short or long rest.

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, Range, Two-Handed, Ammunition (Firearms), Reload, Slow