Cult of the Crushing Wave
The Cult of the Crushing Wave is a group of fanatics and zealots who worship the primordial Olhydra. The cult was founded by a brutal human named Gar Shatterkeel.
The Cult of the Crushing Wave has attracted many who simply see it as an easy route to more plunder and riches for their own personal gain. The core membership, however, is obsessed with the power of water, from raging floods to powerful riptides to the grinding force of glaciers. They see all living beings as little more than water trapped within flesh, and believe it is their sacred duty to return non-believers to the water from whence they came.
Though they maintain an outpost at Rivergarde Keep, their base of operations is the Temple of the Crushing Wave within the ruins of an ancient dwarven city below Orodeth.
In 2966, Drake's Company entered a series of flooded caverns beneath the temple, known to the cult as the Plunging Torrents, and made their way to the portal to the plane of water that lay at its heart. After a pitched battle, the elven cleric Lafiel plunged her dagger into Gar's chest; his body instantly dissolved into inky black water, leaving behind only his trident, Drown. Believing the threat to be ended, they returned to Drakkengarde and gave the trident to a broker to sell. In truth, however, Shatterkeel's death merely cleared the way for an aboleth named Yngukulub the Devourer, a cult adherent living in the caverns, to claim leadership. It mentally dominated every surviving member of the cult, afflicting most of them with a transformative disease that bound them to the water. Yngukulub then sent an agent to Drakkengarde, who purchased the trident and returned it to his new master.
When Drake's Company returned to challenge him, Yngukulub mentally dominated most of them while its minions killed Lafiel. Soon after the aboleth used Drown to summon Olhydra]] into Syra, resulting in the Shattering of Orodeth. Nearly two weeks later, the Brightstone Heroes and Kazak's Follies staged an assault on the caverns, killing Yngukulub and pushing Olhydra back through the portal as it closed. The heroes found that the few surviving cultists had been irreparably warped, body and mind, by Yngukulub; they were subsequently put out of their misery.