Scant Wand of Storms

This magic wand was originally created in the capital city of Onnwal, and has been used against raiding warships from the South Province. Its first creator was undoubtedly influenced by observing the furious weather in the Sea of Gearnat. While you hold this magic wand, you can use a Magic Action to create a 30–foot radius Sphere centered on a point that you can see within range. Since that area is filled by heavy rain and lightning, it's Lightly Obscured and is a Difficult Terrain. When a creature that starts its turn there or enters the Sphere for the first time on a turn, it must make a DC 17 Constitution saving throw, taking 8d8 lightning damage on a failed save, or half as much damage and no other ill effects on a successful one. The Sphere lasts for 1 minute or earlier if you dismiss it with a Bonus Action. Once you use this property, you can't use it again until you finish a Long Rest.

Proficiency: simple, rod Source: Treasures from Oerth p. 25 (Homebrew)