Arcane Laser Cannon

It is imbued with magic like a battery. The amount it can hold is determined when it's crafted. It gains 1 charge for every point above the crafting DC. So, for example, if the DC were 15 and someone rolled a 24 they would get 9 charges. The gun can fire continuously for 1 round per charge.

The blast will do 2d6 force damage per round, however you can choose to sacrifice a spell slot to add xd6 to the damage where x is the level of the spell slot, but you must declare you are spending the spell slot before you roll to hit or the enemy rolls their dex save.

The blast would have the following stats:
Dex based
60 ft line
For the initial attack you must roll a ranged to hit, but even if you miss the beam persists. For each turn after, when you move the beam to a target, it and anyone within the line of the beam must make a dex save. Upon a successful save they take no damage.

Additionally, lenses can be crafted for the laser to change the type of damage depending on the gem used. The lens must be enchanted while being crafted. The list of gems and the damage they transform  the laser to is below"
Ruby - fire 
Sapphire - cold
Emerald - acid
Amethyst - poison
Topaz - lightning
Onyx - thunder
Diamond - radiant
Amber - necrotic

The blaster is a ranged weapon that deals (1d6) radiant damage on a hit. Its normal range is 30 feet, and its long range is 90 feet.

Notes: by any caster., Range