Cult of the Caustic Heart

The Cult of the Caustic Heart is a cult dedicated to worship Tiamat, the Scaled Tyrant.

Goals and organization
The Cult of the Caustic Heart is based in Port Damali. Their leaders are determined to free Tiamat from her imprisonment in Avernus, the first layer of the Nine Hells. To further their schemes, the cult offers power and depravity to grasping and impressionable personalities, and entraps them with contracts and social leverage.

Known members

 * Cirisa - Leader of the cult
 * Calianna Mordsson - Former member/captive

History
The draconic sorcerer Calianna Mordsson, who lived on the streets in Port Damali, was taken in by the Cult of the Caustic Heart, who raised her telling her she was "special and important."

Calianna, having escaped from the cult, bumped into the Mighty Nein in Berleben while she was looking for a ritual artifact of the cult's: an opulent bowl that, when filled with blood, could be used to commune with Tiamat in various ways. The combined party found the bowl in a merrow den in the Labenda Swamp, and Yasha Nydoorin destroyed the item with Magician's Judge.

Explorer's Guide to Wildemount
In the sourcebook, set around, the mid-level adventure hook A Friend in Need involves the cult having caught up with Calianna in the Felderwin Tillage and attempting to sacrifice her to Tiamat. The players interrupt the ritual, and Calianna asks the player characters to help in vanquishing the cult for good.

Trivia
The Cobalt Soul theorizes that there is at least one other bowl like the one this cult wanted to use.