Nicholas Brandt was released from prison in "Wrath".
Nicholas Brandt was a international arms dealer that intended to sell nuclear material to the Egyptian Jihad. Nikita was able to seduce him and they started an affair. She managed to gain his trust and enter his inner circle. Nikita betrayed him and brought him in to Division. Nikita brutally beat him up for payback as he had hurt the wife of one of his employees. As they were unable to find his plutonium he got locked up in a CIA black site. He got tortured for five years but never revealed where the plutonium was and developed a deep hatred for Nikita.
In "Wrath" Roan and Percy visited him and offered him freedom in exchange for the plutonium. Nicholas wanted to pay Nikita back and they freed him to allow him his revenge. With information from them he killed Madeline Pierce with a bomb to her car to draw Nikita out. Waiting at the funeral for Nikita he killed two Division agents and used them as bait. He then ambushed her and captured her. Nikita tried to tell him she was following the orders of Percy at that time and is fighting him now. Brandt said that is not true and that she liked doing that to him, he then proceeded to torture her. Brandt told her how he went through all of the torture thinking about making her suffer one day. His torture made Nikita show a harder side of herself, she admitted she enjoyed beating him up, however the torture of Brandt was not having effect on her. Brandt contacted Percy and wanted him to help her make Nikita suffer. Percy told him how he could capture Michael to make Nikita suffer by hurting him. As Brandt hit Michael an enraged Nikita broke free and attacked him. Brandt was able to knock her down and tried to choke her. Sean Pierce came in and killed him with multiple gunshots.
Brandt was a ruthless arms dealer. He badly injured people to make an example and get what he wanted. He fell for Nikita and was deeply hurt when she viciously beat him up for injuring a woman. While being tortured in prison he developed a deep hatred against Nikita and only the thought about her kept him going to withstand the pain.
After he got out he was willing to put everything aside just to get back at her.
Brandt was skilled enought to kill a heavily guarded senator in broad daylight. He was even able to ambush Nikita and capture her without any notice. Brandt was a powerfull fighter and was able to take a heavy beating and defeat a furious Nikita.