Flavius Appianus

Flavius Appianus was a general to the final emperor. While he fought against the Children of the Wind he was known for his ferocity and at the time was known for given the Appian quarter where surrendered troops were all killed. As a result the Children refused to surrender anymore and started to imitate the Appian quarter.
Being chastised for his ferocity and not following the rules of battle, he slowly grew to distrust the emperor and started to examine other routes to solve the problem.
He betrayed the emperor, looking for more power and became a power in his own right. He experimented with dark powers, transforming himself into a dark lich.
The emperor conferred with the Holy Isles on how to stop him, and they worked together to destroy him. However they did not know he had concealed his soul in a phylactery.
He spent decades rebuilding his powerbase before the empire was aware of him again. This time he tricked them into believing they had destroyed his phylactery and had hidden his base better.
He has been spreading his power throughout the world.