Santos

Agent Santos (first name unknown) is the tertiary antagonist turned supporting character of the 2017 live action film Transformers: The Last Knight. He is the supreme leader and top commander of the Transformers Reaction Force or TRF in acronym, an international government-packed military organization whose main goal is to wipe out every single Transformer in Earth, regardless of faction, but later he helps the Autobots to save the Earth.

He is portrayed by actor Santiago Carbera.

Transformers: The Last Knight
Santos led the TRF on a mission to Chicago when drones detected Transformers there. He encountered Cade Yeager and Bumblebee, but was prevented from apprehending them by three factors: Bumblebee went on a reassembling spree and injured many of his men, William Lennox encouraged him to stand down, and Hound arrived and threatened them with his Gatling gun. Santos had to retreat for the day. He later followed Megatron's Decepticon team into another mission to Cade Yeager's junkyard and pursued the Autobots when they beat it out of there. His TRF forces surrounded the abandoned city Cade was using as refuge. He controlled a fleet of drones which Cade had a heck of a time avoiding, but was forced into another retreat when the mother drone was destroyed by Cade. He then led a squad of TRF troops and pursued the HMS Alliance, which was being captained by Cade and Viviane Wembly. Arriving at the ancient Cybertronian ship, Santos's submarine was forced to use a narrow, perilous tube for entry after the gate closed behind Cade. He managed to make it in and engaged a knight who threatened Cade and Viviane. He then tried to convince Viviane to hand over the Staff of Merlin, only for her to turn the tables on them when she revealed she was the only one who could use it. Santos had to stand down. He rendezvoused with the rest of the TRF soldiers when the ship broke the ocean surface and they were provided with Ospreys to reach the ignition chamber after boarding the Knight Ship the Autobots were using as their main transport. He boarded the same Osprey as Lennox, Cade, and Viviane (and unknowingly Izabella and Sqweeks) and had a conversation with Cade. Having finally understood that his belief about all Cybertronians being enemies was the tragic error, Santos and his soldiers removed the TRF badges from their uniforms threw them to the floorand and breaks the with TRF. Then, the former TRF soldiers, Santos and Lennox reached the chamber and they targeted it with a nuclear strike after suffering many casualties during the final battle against the Decepticons and Quintessa. After the long battle, Optimus gave a speech before heading back to Cybertron using the Autobot Knight Ship.

Personality
At first, Santos is ruthless about the Transformers, both Autobots and Decepticons but in his eyes what he does is right, indeed, he killed Canopy to protect Izabella and the other children present in the forbidden area of Chicago. He is also ruthless with the humans, indeed, after Bumblebee killed some of his men in order to save Cade Yeager and Santos tried to kill him.

However, he changed his opinion when he allied with Cade and the Autobots in order to save the world from Quintessa and the Decepticons. He and the other agents tear the TRF logos out of their suit to make it clear that they no longer posed a threat against Cade and the Autobots.