In 2016, Arturo's organization was contacted by the Assassin team of Galina Voronina. Voronina had a broken leg who needed treatments and needed a discreet doctor while the Assassins were in Mexico hunting their targets and hidding from the Templars.
Viera accepted and sent a pair of doctors to treat Voronina's leg, his girlfriend and unknown to her a Templar agent. Once in the hotel room where the Assassins were hiding, the Templar was killed by Voronina when he tried to pull out a gun from his bag. Sensing that his partner was saying the truth and knew nothing of her colleague's true allegiance, Charlotte de la Cruz knocked her unconscious.
Later, enraged that someone dared to raise a hand on his girl in his city, Viera decided to hunt down the trio of Assassins and sent his men after them. Disobeying Ortega Sanchez, a Templar who told him that the Assassins were theirs, Viera eventually captured Kody, the team technician. He then cut off Kody's ear, sending it to Galina and Charlotte and telling them that they had twenty minutes to surrender before he cut off another part of their friend.
Setting a trap for Charlotte and Galina Voronina in the emptied Estadio Azteca stadium that he rented for the night, Viera, his girlfriend and a dozen of his men waited for the Assassins arrival. Once there, Charlotte used her new Assassins skills to take out Viera's men while the injured Galina was covering her with a sniper rifle. They killed all the cartel members present in the stadium until Viera's girls also began shooting at them with a sniper rifle, and as she was taking cover Charlotte was captured by Viera. Shooting her in the foot and threatening to kill both her and Kody, Viera ordered Galina to show herself.
However as the Assassins ware about to be killed, a Templar's strike team led by Ortega Sanchez arrived in a helicopter, killing Viera's lover and injuring him using a machinegun. While the Templars landed, Viera was crawling on the ground trying to reach the butchered body of his love until Whittaker, a Templar agent, finished him with his gun.
Later, Galina contacted Viera's Cartel and made a pact with them; the head of the man who ordered their boss death in exchange for the protection of Charlotte de la Cruz. During the arranged meeting between Sanchez and de la Cruz where she was willingly surrendering herself to him, the Cartel killed the Templar and his men, avenging Viera and preventing de la Cruz from falling into the Templars hands.