Dark Sun: Trials of Ash and Silt
A ghastly Tiefling and skilled assassin, and "mentor" to Sera.
Originally, Thehk was in the company of House Vordon in Celik, acting as bodyguard and assassin. Once Sera sought him out and initiated the strange apprentice-mentor relationship they now entertain, he betrayed his employer on the grounds of “he had something better to do” and “he was bored.” For quite some time, he continued to linger in Celik when he was not seeking prey or pursuing his agenda securing him in undeath.
For a number of months, Sera was apprenticed to Thehk, and he had converted her to a Revenant, like him, through his experimentation with the Gray and the Obsidian Plain. Once converted, he took Sera away from the party (much to Ubashu’s delight), and began teaching her the dark secrets of death and undeath.
Ultimately, Sera realized her path lie away from her mentor, and she rejoined the party despite Ubashu, and the two have a shaky accord.
Thehk’s whereabouts, however, are as of yet unknown…