Tziz Jarek was an infamous rogue Callidus Assassin who was active during the Wars of Vindication, which took place shortly after the death of the Renegade High Lord Goge Vandire during the Age of Apostasy's Reign of Blood in the early 36th Millennium. Vandire had managed to corrupt many within the Officio Assassinorum, just as he had bribed and blackmailed his way through the other Imperial Adepta. Foremost amongst Vandire's agents was Tziz Jarek. Using the shapeshifting drug Polymorphine, Jarek had assassinated the Grand Master of the Officio Assassinorum and assumed his identity. However, unbeknownst to Jarek, the Grand Master had expected such a plot and had a decoy Assassin take his place in his chambers. As such, Jarek had not killed the true Grand Master, who secretly mustered those