The Jedi who befriend Ciara Santhe in hopes of luring Lucian Odysseus to his death some 20 years before the Clone Wars met his end at the man he was hunting. Known in the order as a good and honest jedi but when his his master died some years before the Clone Wars Cassius became obsessed with hunting and taking down his master's killer. Believing he found the sith in alternative healer Lucian Odyesseus was the Sith behind it he stalked the man for months, noting the intrest he was taking in an unknown doctor and daughter of a Chandrlian supporter of the order Ciara Santhe.
It is not sure which man befriend the girl frist, but both offering her a way to heal her father began to vie for her attention. After the girls father was healed Cassius took Ciara to Dantooine unbeknowst to Ciara to set a trap for the man who bleived killed his master, their firned Luican. Twice the two men confronted each other and in in the end it was Ciara who aided Lucian to seal Cassius fate after Cassius revealed he not Luican had killed her father.
A month after Danntooine the Jedi Order came looking for their lost jedi. When it was suggested by Ciara that Cassius fell to the darkside and murdered her father (even with hinting she had proof) was told by the jedi that was something that Jedi did not do as of 19 ABY Cassius Vexus was considered by the Oder as MIA, having never found his body.