Stormtamer

Weapon (scimitar), very rare (requires attunement)

This basket-hilted cutlass is haunted by the vengeful ghost of a long-dead pirate lord. It can be wielded as a +1 scimitar, and on each hit Stormtamer deals 1d6 lightning damage in addition to its normal damage.

When the wielder is attacked, as a reaction they can swing Stormtamer around them to create a whirlwind in a 10-ft. radius, which surrounds and moves with the wielder for 1 minute. Ranged weapon attack rolls into or through this whirlwind have disadvantage. The area of the whirlwind also counts as difficult terrain for all characters other than the wielder, and a creature entering this area or beginning its turn within must succeed on a DC 14 Strength saving throw or be knocked prone. Small or smaller creatures that fail their save are also pushed 10 feet away from the wielder. This effect can be dispelled as if it were a 5th-level spell. Once this ability has been used, it cannot be used again until the wielder completes a long rest.

The Haunted Blade. A character that attunes Stormtamer is haunted by shadowy dreams of storms at sea the next time they take a long rest, as their spirit is drawn into the Astral Plane (as if they had cast astral projection). There, they encounter the restless shade of the pirate lord, who harangues them incessantly about all those who wronged him in life and upon whom the wielder must wreak a terrible vengeance upon them or their descendants or allies or homelands or whatever targets might be the least bit connected to them. The specifics of who might have wronged the pirate lord in the past should be tailored to fit the campaign world.

During this harangue, the wielder can attempt to pacify the ghost with a successful DC 20 Charisma (Deception, Intimidation, or Persuasion) check. A character who is proficient in History or in water vehicles has advantage on their Charisma check, as they are able to connect elements of the pirate’s story and persuade them that their vengeance has already been met. If the check is failed, the ghost tries to overwhelm their mind with a spirit of hateful revenge, and if the wielder fails a DC 15 Wisdom saving throw they are overcome with a geas to perform some act of ruination upon a person, place, or object connected to some plot of vengeance, such as murdering their old first mate or burning the ship or warehouse of an old rival.

While under a geas, the wielder cannot remove the attunement from Stormtamer, and they are drawn back into the dream realm each time they take a long rest, though their dreams and visions are hazy and indistinct. Once the geas is completed, the next time they return to the Astral Plane the can attempt a DC 15 Charisma (Deception, Intimidation, or Persuasion) check to convince the ghost that they are worthy and accepts them as the rightful wielder of Stormtamer. If the check fails, the ghost attempts to lay a new geas. If they complete this second geas, the DC of the Charisma (Deception, Intimidation, or Persuasion) check is reduced to 10. If it is still failed, the ghost attempts to lay an additional geas on the wielder. Once this third geas is completed, the ghost is satisfied and does not torment the wielder further but accepts their ownership of Stormtamer.

If the wielder succeeds on its Charisma check or on its Wisdom saving throw, the ghostly pirate snarls its fury and troubles the wielder’s sleep with its constant muttering and dreams of savage storms.

When the wielder awakens, they must succeed on a DC 10 Constitution saving throw or gain a level of exhaustion. If the wielder does not attune Stormtamer again, the pirate does not return to their dreams. However, if they attune it once more, the pirate ghost draws them again into the Astral Plane and the process is repeated as described above.

If the wielder successfully faces the pirate ghost on three consecutive nights and succeeds on their Charisma check and/or their Wisdom saving throw, the pirate ghost relents and acknowledges their rightful ownership of the blade.

Once the pirate ghost has accepted a wielder, it can be a source of information, though its attitude is always cantankerous and short-tempered. If the wielder meditates for 10 minutes, they can cast their spirit into the Astral Plane and talk to the ghost, asking it questions as if casting contact other plane.

After using this ability, it cannot be used again until the wielder completes a long rest. Fragments of the pirate ghost’s memories and skills also begin to seep into the wielder’s mind, granting them proficiency with water vehicles and giving them advantage on Intelligence (Nature) or Wisdom (Survival) checks related to the ocean and creatures that live in it.