Viggo Drantyev (real name unknown) was a Russian-born criminal who later became an agent working for Svetlana Chernitskaya.
Much of Viggo's past is unknown but at some point, he met Svetlana who told him of her plans to exact revenge against those responsible for the death of her fiancée, Anatoly Zhukov by killing NCIS Special Agents William Decker, Jennifer Shepard and Leroy Jethro Gibbs.
Viggo agreed to help and as such, became Svetlana's agent.
At some point, Viggo and a team of three other assassins arrived in Los Angeles with Svetlana assisting them. They tracked down Decker and tortured him for information although Decker would not say anything, except the word, "Oshimaida".
To help further his goals, Viggo also used the name, "Viggo Drantyev" as a burn alias.
With nothing else to gain, the group later killed Decker before fleeing while also lying in wait, knowing that Decker's colleagues would attend his funeral.
NCIS Season 5Edit
Viggo made his debut appearance in the Season 5 finale episode, Judgment Day Part 1 (episode) where he was present at Decker's funeral.
His presence greatly unnerved NCIS Director Jennifer Shepard who heard Viggo say, "Oshimaida".
Realizing that this was connected to the Paris mission, Jenny abandoned her bodyguards, NCIS Special Agent Anthony DiNozzo and NCIS/Mossad Liaison Officer Ziva David, instead choosing to off the grid and investigate things further with the help of Gibbs's mentor, former NIS agent, Michael Franks.
Viggo and his men along with Svetlana later tracked down Sasha Gordon, Decker's girlfriend and later tortured Sasha too for information before killing her by pushing her off a small area in Venice Beach with members of the Los Angeles Police Department later finding Sasha's body.
Having gotten information including the fact that Jenny and Franks were searching for answers along with the location of a diner belonging to Decker, Viggo and his men headed for the diner, unknowingly bypassing Tony and Ziva along the way.
When they reached the diner, Viggo and the group split into two in the hope of killing Jenny, only for their efforts to ultimately fail as Jenny managed to kill all three assassins including Viggo himself although Viggo managed to fatally wound Jenny too.