Voiced by: Hidetori Nakamura (Japanese), Bill Jenkins (English)
A friend of Karin's from New York, he is an Armenian-American. He was the one who invited Klaris to help out. He is usually cautious with a wait-and-see attitude. Talsian seems to have a connection to Karin's parents and doesn't talk during their instant message conversations. Talsian makes a physical appearance halfway through the series. He had actually created two Medusas in secret.
He is the chairman of Atlas Corporation and apparently knows Ryouko well. It is revealed that Talsian and Nagiko, the first CEO of Atlas, both helped create Atlas for a better future for their descendants. He is placed under arrest by Ryouko under allegations of having assisted an unknowing Karin to shut down Atlas's critical systems. Sergei is also a Russian name that can means "Servant" which is quite ironic as he is the founder of Atlas.
