Sword of Fathoms

A Sword of Fathoms is a falchion granted to those that have been favored by the leviathan Uk'otoa.

Appearance
A Sword of Fathoms is a one-handed falchion. They are not magical in and of themselves, rather they represent the pact forged between a warlock and their patron Uk'otoa. Its most remarkable feature was that some areas of the weapon were covered in sea weed and mollusks. Moreover, whenever the sword was summoned, a small jet of sea water was shot from the user's hand, and the blade continued producing sea water for as long as it was summoned.

Properties
Though not magical itself, a Sword of Fathoms could absorb other magical weapons and take their properties, as well as some of their physical features. It could absorb as many weapons as the wielder desired, but upon absorbing new properties, the old ones were lost, taken by Uk'otoa. Fjord for example used it to absorb two blades, the Waste Hunter Blade and Summer's Dance. Additionally, a Sword of Fathoms form changes based on the number of Cloven Crystals that its user had absorbed (one yellow glowing eye appeared on the blade per crystal consumed by its wielder).

Campaign 2: The Mighty Nein
Avantika revealed that the blade belonged to Vandran prior to Fjord, and that it was he who named it the Sword of Fathoms.

After Uk'otoa punished Fjord for not putting the remaining cloven crystal in the last temple, Fjord abandoned his pact and destroyed the sword by throwing it into a pool of lava in the Kiln under Kravaraad. While he believed that the Cloven Crystal remaining in the sword was thereby destroyed, that was not the case. In, the Mighty Nein's ship was attacked en route to the peace negotiations between the Empire and Dynasty by several deep scions carrying their own Sword of Fathoms. Fjord was killed and the scions appeared to be stabbing and digging at his chest and attempted to carry off his body. Fjord realized that the crystal was not within the sword that had been destroyed, but remained in his chest. This was confirmed when Caduceus ejected the crystal with a Greater Restoration. The Mighty Nein stored the crystal in Caleb's Vault of Amber to shield it from divination magic.

Tide of Retribution
When the sahuagin Selachai made a pact with Uk'otoa, she was granted a Sword of Fathoms, as well as a magical Rod of Retribution. Selachai's Sword of Fathoms can cause a creature she hits to momentarily choke on seawater.