Born into wealth and privilege on Dromund Kaas, Thana Vesh spent her childhood cultivating an explosive temper and destroying everything she laid eyes on. When Thana discovered her talent with the Force, she tested her destructive talents on her military parents' bodyguards. After the eighth guard was found broken and mangled, Thana's terrified parents tried to suppress their daughter's power; Thana lashed out, and the resulting devastation burned an entire Kaas City block to the ground.
Thana's parents were consumed in the blaze and their Force-adept orphan was sent to the Sith Academy on Korriban. The incident was widely publicized as an example of the terrible fate of parents who fear, rather than embrace, a potential Sith child.
Thana tore through her Sith trials and fellow acolytes at lightning speed, earning the attention of Darth Gravus. When her studies concluded, the elder Sith Lord took Thana on as his apprentice with the promise that she would finally sink her teeth into the Republic in the jungles of Taris.