Captain's Shell

Magic Resistance. The armor has advantage on saving throws against spells and other magical effects.

Bound to the Ship. The armor cannot willingly move more than 300 feet from its ship. If it is, it becomes paralyzed until it is returned.

Spectral Presence. The armor is animated by the captain's spirit. As a bonus action, it can target one other friendly construct it can see within 60 feet. The target construct can immediately use its reaction to make one weapon attack.

Multiattack. The armor makes two attacks with its Cursed Cutlass.

Cursed Cutlass. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) slashing damage plus 7 (2d6) necrotic damage.

Fathom's Call (Recharge 5–6). The armor releases a wave of spectral, chilling fog in a 30-foot cone. 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 is restrained by spectral chains for 1 minute. On a successful save, the creature takes half as much damage and is not restrained. A restrained creature can use its action to make a DC 15 Strength check, freeing itself on a success.