Arcane Cannon: Frost Shot

It takes one action to aim the cannon and one action to fire it. After the cannon has fired, it must recharge for 5 minutes before it can be fired again.

Frost Shot. The cannon shoots a ball of frost to a point you can see within 1,200 feet of the cannon. The ball then expands to form a 30-foot-radius sphere centered on that point. Each creature in that area must make a DC 15 Constitution saving throw. On a failed save, a creature takes 22 (4d10) cold damage, and its speed is reduced by 10 feet for 1 minute. On a successful save, the creature takes half as much damage, and its speed isn't reduced. A creature whose speed is reduced by this effect can repeat the save at the end of each of its turns, ending the effect on itself on a success.