Sergei is an officer in Umbrella. During his army days, he held the rank of colonel and is still called that on occasion as a nickname. He approached Umbrella after the fall of the Soviet Union, looking for work. He is involved in Tyrant research, and his experience in military affairs made him instrumental in the founding of Umbrella's private militia, the Umbrella Biohazard Countermeasure Service (U.B.C.S.). Nicholai Ginovaef is one of his subordinates. He shows an ardor for following Ozwell E. Spencer's orders and makes sure even the most radical of Spencer's wishes are carried out.