In Vox Machina's first adventure, the group was hired by Fendril Vas in Stilben to investigate the seemingly dubious and dangerous new business conglomerate called "the Myriad". Vox Machina eventually entered a chamber housing a planar rift that pulled the group into a room with Crysa-Thul. Fendril was actually a worshipper of the stillborn god and had intended to feed the party to this deity like many previous mercenary groups. Vox Machina destroyed Crysa-Thul and returned to slay Fendril for his treachery.
↑Matthew Mercer spelled the name as both "Crysa-Thul" and "Crysa-thul" on his Vox Machina Wiki (see "Fendril Vas" and "Stilben"). The former is used on this wiki because it was Mercer's most frequently used form.