Victor Ulyanov (Son)
Ulyanov son Victor was killed in Columbia at the start of season 4 by Scott and Stonebridge of Section 20.
In Episode 3 Victor's body is delivered to Ulyanov's home in Southern Moscow and Arkady wanted revenge so sent Skander to deal with them however Skander is eventually killed by Scott and Stonebridge in episode 6.
At the end of episode 6 it is shown the Arkady is in league with terrorist leader Al-Zuhari and is making a virus that has no cure that can infect the people of the west with.
In episode 7 Scott and Stonebridge get arrested and sent to a prison that Ulyanov owns but using alases Ulyanov doesn't detect them until CIA agent Leo Kamali compromises them which forces them to escape from the prison.
At the warehouse were Ulyanov is making the virus 20 attack along with Pirogova and take the warehouse but Ulyanov escapes with the virus.
In episode 9 Ulyanov finds out the 20 are in Berlin and travels there to kill Scott and Stonebridge.
In Season 4, Episode 10: He was killed by Nina Pirogova.