Five years after the Nanite Event and his mentor's sickness, Agent Six left the Six and worked in Providence with White Knight as his partner. One day, he fought an unusual giant mechanical EVO, after it exploded he discovered a young Rex Salazar. He brought him to Dr. Holiday since the boy had the ability to cure EVOs. Since then he became Rex's mentor and promised to help him discover his forgotten past.
After leaving The Keep while Rex was fighting the Multi-faced EVO, Six alerted Rex about the endangered civilians. When he realized Rex couldn't save them he unsheathed his swords and performed a series of acrobatic feats, cutting and moving the debris in mid-air so that they wouldn't fall onto the civilians.
When back at Providence Headquarters, he talked to Dr. Holiday about Rex and learned that Rex's lack of discipline was simply because of the pressure placed on him by Six. He commented that Rex simply needed to learn to control his emotions.
After Rex escaped, Six and other Providence agents found him with Noah. Spotting The Pack attacking, he moved Rex out of the way of one of Skalamander's crystal spikes. Being unprepared for the battle, he lost Bobo Haha, Rex, and Noah through one of Breach's portals.
Later he came to the rescue of Rex, Bobo, and Noah. After giving Bobo his laser pistols he battled Breach. While initially being on the losing side of the battle, he gained the upper hand after unsheathing his swords and throwing them through two of her portals, knocking her unconscious.
He picked up Rex after he played basketball with Noah, then brought him to the Headquarters and warned him that what he was about to show him was disturbing. With Dr. Holiday and Rex they studied Peter Meechum's victim, learning about his history.
Under White Knight's order, they went to New York, confronting Meechum's army. Rex failed to do his task since he was controlled, things went worse. Under Dr. Holiday's guidance Six tried his best to avoid Rex's contagious infection and protecting him. Things went worse when Bobo was zombified. White Knight then ordered the Bleach Protocol, a tactical nuclear weapon that would wipe out the area. Rex argued with him and tried to convince him that there was something more about Meechum. Six refused to waste more time since Meechum was getting close in crossing the bridge.
In the end, Rex succeeded in convincing Meechum to trust him and stopped the Bleach Bomb before it exploded. After he went to search for Meechum's daughter, Bobo discovered that Agent Six had already stopped the bomb in the first place by taking the key. Six destroyed it and agreed with Rex that "Sometimes orders aren't orders."
Agent Six joined Rex and Dr. Holiday in the morning meeting routine in the Providence War Room. They were listening to Captain Calan's briefing. He hit Rex's head when he was bored, warning him that these briefing would be normal procedure. When Rex escaped to Cabo Luna with Bobo, Six asked Dr. Holiday about his whereabouts. She answered that Rex's tracker went down. Six then mentioned that Rex took interest in one of the locations during their previous morning meeting with Calan. Having an idea, he ordered the grunts to scan all the resort area for his biometric signature.
Six found Rex who was waiting for Circe at a restaurant in Cabo Luna. He was surprised that Rex gave in easily when he asked to come back to Providence. At first Six scolded him for being responsible but then said it was completely normal. He felt awkward, mistaking Rex's rebellious act because of his hormones. Rex confessed that he wanted to have fun because he wanted to feel normal, which Six replied that his "normal" was different.
When Rex heard Circe's siren power, he asked to deal with this alone and Six let him. He returned helping Rex when Biowulf strangled him. He then ordered Rex to go after Circe while he fought the Pack with Noah and Bobo. When Circe left with The Pack, Agent Six brought his jet and offered Rex another few days which he declined. Agent Six then told Rex that his feelings for Circe were normal, something that he was looking for the whole time.
Agent Six helped Rex fight Foul Mouth, a mutated bald man in Valley Market. When Rex's powers went off he asked Dr. Holiday for assistance, but she was away in The Hole visiting her sister. When they returned to Providence, Six brought Noah in the corridor of White Knight's office. After his meeting with White Knight was over, he escorted him outside but met Rex instead. He helped Noah keep his secret by telling Rex that he brought him to Rex.
After Noah and Rex opened the lock of the Hole, Agent Six received a distress call from Noah. When trying to calm him down Noah blurted his secret that he fought with Providence. Through the phone, Six guided Rex to open another alternative escape.
Rex succeeded in opening the passage and Six with a few agents welcomed them, but Noah was kidnapped by the Spider EVO Agent Six and his team went looking for them as he ordered Rex to stay. When he found the Spider EVO who was defeated by Rex, he ordered his team to restrain it carefully, ignoring White Knight's wishes to eliminate it. Dr. Holiday was grateful for his mercy, but still felt resentment because of White Knight's idea about Noah. White Knight asked how Rex found out about Noah being his spy. Noah almost said something but Six covered for him, saying that it was his fault.
Agent Six asked Dr. Holiday if there was any sign of Rex. She couldn't find him and complained that Six and the Providence had been using him. He then asked Bobo knowing that the monkey would hide his location. When Bobo refused to say anything, he warned him that even though White Knight wouldn't harm Rex, Bobo was expendable.
Bobo gave in but he misled the agent to a different location. When Six returned to Providence, he bribed Bobo with pizza as the monkey quickly told him the exact location. Before he left, Dr. Holiday asked him not to take Rex back. She said that it had to be his decision. Agent Six arrived in the deserted area reporting to Dr. Holiday that he didn't see anything until the village was suddenly revealed.
Six located Rex in the architect building. When White Knight asked through his ear communicator, he reported false information, saying that Rex wasn't there. He was willing to let Rex stay in the village, but Rex preferred to return with him to Providence. While flying to the Headquarters he rejected Rex's changes request except eating meatloaf and mashed potatoes every Friday like a real family. He was last seen eating together with Rex, Dr. Holiday and Bobo, though he complained that the food was a little dry.
When Rex was in danger of a nanite overload, Six tried in vain to stop him from curing a Pyreptryx that would have triggered the overload. He took Rex to a dropship to take him to Paradise base. Once at Paradise, Holiday had to threaten the head technician Weaver to get Rex his treatment.
While Rex was getting the excess nanites extracted from his body Weaver and his crew jumped Six and the others with sleeping gas, but evidently didn't go quietly as shown by the mess left behind. When The Pack showed up at the base Six immediately got into a fight with Biowulf.
However, Dr. Holiday broke up the fight pointing out delicacy of the nanite tank, especially when Weaver pointed out that it was full of active nanites which he tried to use to force Six and the others to leave. However Weaver's bluff proved to be too good; he accidentally absorbed the nanites in the tank while making it look realistic.
Weaver was transformed into a massive hulking EVO Rex tried to cure Weaver but it triggered a second overload forcing Six to take Weaver down by striking him in the head with his sword. Afterwards Six and the others took Rex to Paradise's backup Purgatory in the desert.
Six joined Rex on an attack on Van Kleiss who had just violated New York City's airspace. Six fought against Biowulf inside the Blimp up until Six learned that Van Kleiss and the Pack were there on diplomatic immunity at which point he stopped Rex from attacking Van Kleiss. Six later attended a meeting with White Knight, Dr. Holiday, and Rex about Van Kleiss back in Providence.
While everyone unanimously agreed that Van Kleiss was using his diplomatic immunity for some nefarious scheme, they could not do anything, legally, until he waved it. Instead, White Knight intended to take advantage of an invitation for Rex from the Abysus Embassy. At first it was Six and Dr. Holiday that should be in the party guest to find out what Van Kleiss was planning.
In the end Rex locked Six into his closet and stole one of his suits to go to the party himself. Six later arrived in front of the EVO Embassy building with Bobo. With the chimp's help, Six was able to sneak into the embassy party. He met Dr. Holiday who explained Rex's absence in search of Circe. When she waited for a compliment, Agent Six flatly said that she looked nice. Unfortunately it was shortly before the party ended and Six was forced to leave without Rex.
The next day Agent Six and most of the Providence Grunts secured the building. When Van Kleiss made his power play Six helped fight off an EVO Van Kleiss had smuggled in. After the EVOs were defeated and Van Kleiss retreated back to Abysus, Six arrived at the harbor congratulating Rex, before realizing that Rex dived into the harbor wearing one of his suits.
Six, Bobo, and Rex were investigating a nest of EVO Scorthius when Breach appeared and snatched Rex, leaving Six and Bobo to fend for themselves. Bobo accidentally woke the Scorthius. They were narrowly saved from the Scorthius when Breach dumped some of her junk on them, in the process spraying them with Scorthius guts.
Six, Bobo, and Rex were called into Hong Kong to halt the rampage of a ferocious EVO when suddenly the EVO returned to human form. Six tried to calm the panicked man down but he ran off into traffic. Back at Providence, Six was informed of similar incidents by White, and it was believed a Nanite Project scientist named Gabriel Rylander was responsible.
Providence managed to track Rylander's base to somewhere in the Amazon jungle and Six, Rex, Dr. Holiday, and Bobo were sent after him. Six talked to Rex and Holiday about Rylander, both Holiday and Rex were hopeful about Rylander: he could very well be Rex's long lost father and Rylander's nanite research presented a possible cure for EVOs. Six however was wary of Rylander knowing that he was dangerous.
During the trek the group was attacked by EVO piranha and Rylander's robotic sentinels. Both times Six managed to hold his own but it was Rex who ultimately saved the group on both occasions. The group eventually reached the base but so did Van Kleiss and The Pack. Six and Biowulf exchanged blows but Six was able to get into Rylander's base and help Rex out in time for the base to be destroyed. Six reported that Van Kleiss was killed in the explosion based on what Rex saw.
Six was part of the strike team sent into the Bug Jar to retrieve a data rod containing valuable tactical information about EVOs. Originally Six was supposed to circle the Bug Jar and Bobo was supposed to blow a hole into the shield with a Broiler when Rex was able to retrieve the data rod.
Unfortunately an EVO was able to shoot down the drop ship and make it crash inside the Bug Jar. Stranded until a new dropship arrived, the group decided to regroup with the agents already inside the Bug Jar to make a stand against the EVOs. They found that the captured agents were being forced to repair the dropship under the supervision of the EVOs' leader NoFace.
Rex and Six fought NoFace and barely got away alive. The group made their last stand on top of a decrepit hotel and were only narrowly saved by the arrival of the third drop ship. Six was also present when Rex pranked White.
Six was present at Rex's briefing to discuss the Rabbit EVO that was harassing Rex. He was shown to be surprised when Rex stated that he was going to Noah's prom. He was also shown to be annoyed when Rex took one of his suits again to go to prom.
Six and Rex were sent to investigate a string of bank robberies by a trio of EVO criminals. He and Rex got into a scuffle with the trio in the middle of their robbery. He was reluctant to send Rex in undercover to infiltrate the group but his judgement was overruled by White Knight. After Rex took down the crime ring behind the robberies, Six gave him a diary to keep track of his life to help him cope with future blackouts.
Six and Rex dealt with a Flea EVO on a rampage in a suburban neighborhood. Once defeated Six used reverse psychology to get Rex to try and cure the EVO Though nearly successful the EVO was killed by Hunter Cain. Six broke up a potential fight between Cain and Rex and took the latter back to Providence.
Once back at HQ Six and White discussed Cain. Six in particular cited him as a threat due to his turning of public opinion against Providence and in particular Rex. Later on when a group of phantom-like EVOs attacked the docks, Six led a strike team to deal with them and was narrowly saved by Rex who up until that point had lost his faith in humanity. With the aid of Hunter's army, Six, Rex and the remaining Providence agents defeated the EVOs.
Agent Six appeared with some of the agents who were watching the live broadcast of Dr. Holiday and her team working on the altered nanites when it was taken over by Zag RS. At the end, he made sure that Holiday and Pete Volkov were rescued by the Providence agents sent to get them.
Six spotted Rex and Bobo as they were hijacking a ship to fly to Abysus to investigate a distress call from Circe. Realizing he couldn't stop them he instead requested that they wait. With Dr. Holiday's help he did a satellite scan of Abysus which they learned was destabilizing. Knowing that White wouldn't approve a mission into Abysus, Six instead sent Bobo on a separate assignment. Bobo would take the group's communicators and send White, if he should come looking for them, on an extended wild goose chase.
The group flew to Abysus where they learned that without the late Van Kleiss to keep it under control that it's instability was spreading. The group was attacked by a massive EVO created by the instability. Alongside remaining Pack members Biowulf, Skalamander, and Circe, the group defeated the EVO.
The Pack took the group to Van Kleiss's old castle where Kleiss left a contingency plan for just such case of emergency, a machine designed to revive him. Naturally Rex refused to revive Van Kleiss instead trying to "cure" Abysus like he would any other EVO nearly drowning Six, Holiday and Circe in nanite goo in the process. With no other choice Rex revived Van Kleiss and subsequently cured him before he escaped with Breach's help.
With the madness dealt with, the group flew back to Providence, both Rex and Six agreeing that they would never understand women.
Agent Six joined the rest of Providence in trying to stop the rampage of Lomitle across China. As per the Lomitle's reproduction cycle for every one of the EVO insects they killed two more took its place. Worse yet, the bugs were adapting to their tactics, becoming progressively harder and harder to kill.
Along with the rest of Providence, Six made a last stand against the bugs at the Great Wall of China, though it did virtually nothing to even slow them down and Six ordered a retreat. Once realizing that the isolated tracking tag, reverse-engineered and mass produced by Doctor Holiday, from the bugs could be used to trick them into eating each other, Six ordered that bombers and Broilers be adapted to spray the bugs thus ending their rampage.
Agent Six was briefly shown unconscious on the bed, affected by the unusual plague with Bobo beside him. After Rex and White Knight cured the Plague EVO, it seemed he had been cured.
Agent Six thinks back on the anniversary of his birthday and the day he had found Rex. At the end, he gives Rex a gift of his very own; a tanto with the words "whether for good or ill, our fates will follow the same path".
Six led an attempt to covertly transport unstable nanites to Providence Headquarters. The plan was for him to drive a decoy truck carrying toilet paper while Rex, Noah, and Bobo, unknowingly, carried the nanites in a beaten up ice cream truck. Six's group was attacked by Gatlocke and his Anarchists after Rex's group was separated from them.
Six was able to give a warning to the group in which he informed Rex that his group was transporting the nanites, and warned them they would go off if they went above sea level or were handled roughly, and now Gatlocke was after them. Later, Six appeared again where he cleared up the earlier misunderstanding. When he said the nanites would go off he meant they would turn off, which they did.
With this Six joined the new escort taking Gatlocke and his men to prison as Rex, Bobo, and Noah got lost in the desert again.
Agent Six participated in the fight against Van Kleiss and the Pack when they invaded the HQ. Van Kleiss mentioning the desire to transform Six and add him to the ranks of his EVO army. Unlike most of Providence's personnel Six wasn't transformed and helped Rex against Van Kleiss.