He was portrayed by Academy Award winning actor Mark Rylance.
In the film's beginning, Jim Terrier and his assassins team are a special black-ops crew under the cover of an international mining company which providing security to local projects. In 2006, their bosses, Terry Cox and Felix Marti, tasks them to end the life of Congo's Mining Minister in order to ensure the team's access to the rich mineral resources, an operation called Calvary, however Felix will choose who will shoot the Minister and the shooter will have to leave Africa, Jim is choosen and he has to leave the continent, leaving his girlfriend Annie behind so he asked Felix to take care of her.
Eight years later, the team was dismissed and Cox himself founded an international security firm called "Aquila Corp". As he found out that Jim wrote a notebook of the entire operations that the team has executed and even took some recording files containing Cox, Cox himself then sent his own assassins to eliminate Jim.
Right after that Stanley, Jim's longtime friend welcomed him and his wife Annie, Stanley gave him information about Cox's company and his new occupations. He added in his things, saying that Felix is a part of the scheme to kill Jim, and states that Felix wants Annie for himself. Afterward, Jim arrived to Felix's house, there, he confronted him while the latter is overwhelmingly drunk. Shortly after this, a special team of ex-US Marines working for Cox as his assassins, attacked the house, which eventually led to Felix's death. After Felix died, Cox meets with Jim at an aquarium where Cox reveals his plans to Jim before he shoots Cox in the left hand, Cox' men arrive to the rescue and Jim escapes, theCox's men kidnapped Annie and he brutally murdered Stanley. Then, Jim gave Cox an ultimatum; let Annie go alive in exchange for Jim's recording files containing Cox giving the team orders back in 2006, what will change the world's look upon Cox's company forever. Cox agrees to the ultimatum and Jim tells him to arrive to a bullfight in Spain.
Upon their arrival to the bullfight stadium, Cox, who's holding Annie as hostage, sends his men to search after Jim. As they are doing it, Jim manages to kill them one by one despite his medical problems. After killing the entire team, including Cox's personal henchman; Reiniger, Annie takes advantage of Cox getting distracted by this and escapes, Cox persues her to the bull's stables.
Prior to Annie's return to Jim, he shoots Cox in the arm and the shoulder making him drop his gun, Annie accidentally opened the doors trying to reach for Jim that quickly released a raging big black bull. Cox sees this and tries to reach for his gun but the bull stormed to get out for freedom and ended up with sticking his horns inside Cox's chest and body, brutally killing him and still attacking him on the ground before leaving him dead on the ground.
Jim delivered the recordings to Interpol agent Jackie Barnes, Aquila Corp was unmasked and lost all it's credibility, however Jim still had to go to prision after attending Stan's funeral.
Cox is a very corrupt person, who cares about getting his orders done and doesn't want any disturbing incidents. Despite being very corrupt, he is also an extremely powerful and ruthless individual, who even antagonized Jim and brutally murdered his best friend Stanley and also he drugged Annie.