Whalefall Armor (Patreon)

Armor (half plate), very rare (requires attunement)

This armor is made of repurposed whale bone and lashed together with salt-stained leather strips. While wearing it, you have resistance to poison damage and gain a swimming speed equal to your walking speed. If you're underwater, you also have advantage on any Wisdom (Animal Handling) or Charisma check you make to interact with beasts that have a swimming speed.

Charges. The armor has 5 charges for the following properties. It regains 1d4 + 1 expended charges daily at dawn.

Spells. While wearing this armor, you can use an action to cast one of the following spells (save DC 16): false life (2nd-level version, 1 charge), insect plague (4 charges; the insects appear as a massive swarm of rotting quippers), or stinking cloud (2 charges).

Bakekujira. While wearing the armor, you can use an action to speak its command word and expend any number of charges from the armor, including 0, to summon the spirit of the whale used to make its bone plates. The spirit appears in an unoccupied space that you can see within 30 feet of you. It uses the statistics for a killer whale, except that it's undead, is immune to poison damage and the poisoned condition, and has a flying speed equal to its swimming speed. It obeys your mental commands to the best of its ability (no action required by you), and takes its turn immediately after yours. If you don't issue any commands, the spirit defends itself from hostile creatures, but otherwise takes no actions. The spirit disappears in a cloud of marine snow after 1 minute. It disappears early if you use an action to dismiss it or if it's reduced to 0 hit points.

When the spirit disappears, roll a d10. If the result is equal to or less than 5 + the number of charges you expended as part of the action to summon it, it disappears as normal, and the property can't be used again until the next dawn. If the result is higher than that number, the spirit becomes hostile to you; it remains for 1 additional minute, can't be dismissed, and immediately regains half its maximum number of hit points. When this happens, this property of the armor can't be used again until 1d4 + 1 days have passed, during which time the number of charges the armor regains each day is reduced by half (rounded up).

Stepping off his skiff at the center of the bay, Valdis let his barnacled weights pull him beneath the surface. In decades past these waters served as a busy port, but were now only known as a ships' graveyard.

As he joined the wrecks along the seabed, the water grew clouded. The sense of rot grew sickeningly strong, even through his helm. In his hands were his violin and bow: when he played, it released a steady tone that bent and dispersed the miasma. He landed in a space free of wreckage and marine fog, but scarcely found his footing before a swarm of decaying fish began to tear at him.

With a wild crescendo, he shifted the current to lift him to a barnacle-crusted stern. The shoal didn't follow as he landed, leaving him free to take stock. If this was a spirit's work, it held great power, and greater malice….

His eyes caught a figure—its armor a shock of bone-white amidst the depths. Its arms rose; behind it, a massive shadow coalesced from the necrotic flotsam.

Valdis grimaced. This was no spirit, at least not on its own. No: this was to be a fight.