Getting involved in the assassination of Theos Orpheus was the worst and best decision of his life. It put him at the center of the chaos that erupted as the war for Azhar and allowed him to push his spymaster talents to the limits.
Managing to adapt to the ever changing, lethal situation allowed Dorian to reap many rewards post-war. Working with Denis and Daniel was eye opening for him, allowing to learn many new things, expanding his already decent skill set.
Building new networks, not only on Azhar but beyond taught Dorian how to handle smuggling groups, deal with all sorts of "undesirables" and helped him put Hades spies in many other courts and begin lending them towards other noble Houses.
In the advent of being awarded Syrak, he had to leave the Lord Commander's court to personally manage the city. While this took him far away from the center of planetary intrigue, it also gave him new avenues for expansion of his personal arsenal.