Vincent Kerraslav is the president of Asteria, and puppet of The Underground.
Deal with the Devil
Vincent Kerraslav was losing his campaign to become president, as people were voting for more extremist parties (which worried Vincant). As a result of his desperation, he made a deal with Voran Sicarius, ensuring he would win the election. In exchange, he had to do regular favours for Voran.
Vincent, despite being a puppet of the Underground, isn't actually very malicious in nature. He is fairly weak and submissive, and as a result, is easy to threaten or influence. This has made it easy for Voran to take advantage of him.