Scrollcase Canon

This cylindrical leather case is imbued with
magical dwarven runes. This item has {7} charges.
While holding it with both hands, you can use an action to expend a charge to either cast the catapult spell (save DC 8+Intmod) on an object inside the
case or {x} charges to fire of its special scroll ammunition. You may attune to the scrollcase to
add your proficiency to the spell DC.
The scrollcase regains 1d6+1 expended charges
daily at dawn. If you expend {x} charges, roll a
d20. If it doesn't