This mace isn't much more than an stormpike shell on a stick, but it gets the job done. Druids and rangers modify the transmutation enchantments embedded in the rod to regrow the shells to their preferred shapes.
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Shell Shock
Weapon (mace), rare (requires attunement)
You have a +1 bonus attack and damage rolls made with this magic weapon.
Shell. While you wield this weapon, you can use an action to launch its shell in an high arc at a point you can see within 20 feet of you. The shell shatters upon impact. Each creature within 5 feet of the target point must make a DC 15 Dexterity saving throw, taking 4d6 piercing damage on a failed save or half as much on a successful one. Once you use this property, you can’t use it again until the shell regrows. It regrows daily at dawn and once per day, it can also regrow if submerged in natural saltwater for an hour. Until the shell regrows, the weapon is considered a club.
Shock. Whenever you hit a target with this weapon while its shell remains, you deal an additional 1d4 lightning damage.