In his position in the Tower of Night he was assigned as cage-handler, and assigned to manuever caged prisoners to their deaths. He was a ruthless person, and he distrusted his own employees.
Styx was assigned by Orbix Xaxis to handle the execution of Xanth Filatine and Magda Burlix and the greatest exeuction of them all, the planned Librarian execution. Styx got sweaty and nervous when approaching executions because of how he himself might be put in the cage if he messed things up. He worked hard knowing his own life was at risk. He was in such fear of Orbix Xaxis that when he had been on night watch four hours and frozen to his seat he suddenly sat up when the High Guardian appraoched, because of his fear of him.
Styx incurred the High Guardian's pleasure, however, when Xanth and Magda were deposited on the Rock Demons' ravine. Orbix told Styx that with his "skilful cage-work" he had sealed their fate.
Like all other Guardians, Styx met his end when the Great Storm hit the Tower of Night and killed Orbix Xaxis, razing the Tower down to the ground.