Arcane Thundersling

You gain a +2 bonus to attack and damage rolls
when using this weapon, which counts as a hand crossbow for the purpose of determining range
and proficiencies, but deals 1d10 thunder damage
on a hit. When fired, an boom emanates from the thundersling that is audible up to 300 ft away.
The thundersling uses a small arcane crystal with
6 charges as a power source. Once the charges
are used, the crystal disintegrates and must be replaced, requiring a standard action.