Locus is often seen as a merciless and cold individual, which causes others to often see him as an enemy or terrifying. Despite his aloof behavior, Locus has developed quite a few unique relationships with specific characters.
Charon Industries[]
Felix[]
Beginning during their time in the UNSC, Locus and Felix never got along, though the two mercenaries have been shown to work very well together. After the Great War, Locus and Felix partnered with Siris and became bounty hunters, hunting criminals and trading them in for profit. In Club, the two mercs fought in sync with each other, though were constantly bickering. Despite this, they were able to complete their mission of capturing Gabriel Lozano. They seemingly had a deep respect for each other, although it would later be revealed that Locus was the only one who had genuinely respected the other or even had a true honor code. Later on, Locus and Felix were able to continue Chorus' civil war, elude the people they work for, and complete certain tasks and missions convincingly, though they still had their differences.
Despite their partnership, the two mercenaries continue to yell at one another and seem to have little respect for each other as well. For example, while Locus prefers to be quick and efficient in his missions, Felix prefers to be dramatic and toys with his victims, causing tension between the two. Oftentimes, Locus is usually the one to get Felix focused on the task at hand and finds many of Felix's decisions to be naive.
After the Great War, Locus was a broken man; a fact, which Felix exploited by manipulating Locus into staying together with him, claiming that they needed each other. However, this was just Felix's way of keeping himself alive. By preventing Locus' psyche to heal from his PTSD, Felix was sure that Locus would keep supporting him when Felix went in over his head and thus kept him in check. Locus realizing that he did not need Felix was, in fact, the latter's greatest fear. Upon learning this and realizing the effects of Felix's influence on himself, Locus abandons his partner to his fate.
Since Felix's death and the former's loss of influence over him, Locus's mind seems to have reached the stage of Post-Traumatic Growth, having since become stronger than the sum of his trauma. Locus even swore to never kill again in Season 15.
Malcolm Hargrove[]
Locus is shown to be very loyal to Control, and describes him as "a man of business." Even during times where the space pirates' plans appear to be in jeopardy, Control is shown to always have a backup plan. Due to this, Locus sees Control as a source of guidance, commonly asking his superior about what their next move should be and appears to trust his judgment. For example, when the Feds and rebels learn of the pirates' involvement in the civil war during Fed vs. New, Locus, rather than retaliate against the Blood Gulch Crew, follows Control's protocol and retreats with Felix. In the end, however, Locus refuses to continue killing people and ultimately betrays Control by allowing the Reds and Blues to transmit their message at the Communication Temple.
Sharkface[]
Sharkface and Locus don't interact much but there is definitely a relationship between the two. Locus appears to merely regard Sharkface as a business partner but does know how much Sharkface can help in their operations. Sharkface, however, seems to have little respect for Locus and likely only does what he is told by Locus in order to get to Carolina and Washington.
Aiden Price[]
Although the Counselor and Locus have only had a few conversations together, Locus and Aiden Price appear to have some level of mutual respect as Locus is willing to listen to Price when the latter has a suggestion. One example of this is Price's plan to use Sharkface as a weapon against the people of Chorus by cultivating his hatred towards Carolina. However, later on when Locus asks Counselor about the Meta, Price questions Locus on his change in behavior ever since his trip through the gateway. Annoyed, Locus states that he is fine and informs Price that he is overstepping his boundaries.
Red Team[]
Grif[]
Locus initially saw Grif as little more than a small obstacle, but over time he saw that he and the other Reds and Blues posed an actual threat. Upon learning of the Reds and Blues' whereabouts from Lopez, Locus went to Grif to get his help. However, Grif at this point was completely insane due to isolation, guilt, and boredom. Locus is heavily annoyed with his antics but was still willing to cooperate with him, even taking the volleyball replicas Grif made of his friends with him. They're shown to work together greatly, with Grif creating a diversion while Locus rescues Wash and Carolina. After Locus frees Grif and the others from imprisonment, Grif expresses full trust in him.
Sarge[]
Originally Sarge and Locus met on the battlefield of Crash Site Bravo and was one of the Reds and Blues taken by Locus to the Federal Army of Chorus. Sarge mentioned absolute distrust in Locus, implying a desire to shoot him. However his suspicions were confirmed when Locus and Felix incinerated the middle base they were stationed in. He along with the Reds and Blues, expressed great desire to kill Locus and Felix, but Felix's betrayal far overshadowed Locus's.
After Chorus Locus joined Grif for a rescue operation, in which Sarge was en route to do as well. Sarge replying to settle the leadership of the mission by rock, paper, scissors. Locus won and was complimented, but Sarge stated that it was expected from his cunning and murderous tendencies. Sarge later botching a speech asking for forgiveness irritated Locus due to the small window of time, even going to sarcastically say he was moved and believing in the speech. Upon reaching the hanger, Sarge had desired to provide cover, but was corrected by Locus, due to his shotgun's low range.
Lopez[]
Despite being one of the few people who can legitimately understand Lopez, Locus at first viewed Lopez as another incompetent soldier. His attack on the Reds and Blues at Crash Site Bravo, the destruction of Freckles and his claim that robots like Freckles (and by default Lopez) cannot be murdered since they are machines garnered Lopez's animosity and insults.
Locus was willing to put up with Lopez's insults, until he had called him "crazy", to which Locus denies it revealing he is bilingual. Lopez in turn becomes terrified of Locus, because of his intimidating demeanor and being the only one at the time who can understand his insults, begging Locus not to kill him which usually contradicts his apathetic nature.
After Chorus, Locus was able to rescue Lopez from drifting into a blackhole. Being one of the few people at the time to understand him and in need of help; Lopez revealed the whereabouts of the Blues and Reds, the imprisonment of the Freelancers and Reds and Blues, and the location of Grif.
Blue Team[]
Washington[]
Locus appears to have a fixation on Wash, generally addressing him most of the time in The Federal Army of Chorus, in addition to a journal entry that focuses exclusively on Wash's status. Locus is demonstrated to have a considerable amount of knowledge of Wash's personal history, accurately recounting his betrayal of the Blood Gulch Crew to save himself, and how he was one of the few survivors of Project Freelancer without going into hiding. The main reason for Locus' borderline obsession with Washington appears to be Wash's compassion for the Reds and Blues, and how he believes that Wash was once a greater man before joining the crew. Locus sees his loyalty to the simulation troopers as a weakness and is confused as to why he decides to fight for them.
In Season 13, Wash manages to outsmart Locus several times, deepening Locus' hatred for Wash. During their battle at the Purge, Locus attempts to stab Wash, yelling at him to "Just die!" Seeing Locus' aggression, Wash explains to Locus that killing him would only prove his point of Locus being a true killer.
After Carolina and Washington become trapped by the Blues and Reds, Locus was the one who freed them. Interestingly, Washington was less hostile to Locus than Carolina, due to his heavily dehydrated and starved state, making him delusional and unable to see reality. When Washington gets shot in the neck by one of the Zealots and begins to bleed out, Locus' quick thinking saves him as he calls in his ship A'rynasea to take him to the nearest hospital; proving that Locus has grown to care about his former sworn enemy.
Carolina[]
In Lost But Not Forgotten, Carolina posed as Control in order to convince Locus not to kill the captured Reds and Blues, but Locus becomes suspicious of his "superior". Based on the fact she rescued the Blood Gulch Crew from his team in Cloak and Dagger and their battle in Fed vs. New, Locus seems to dislike Carolina. The two battle for a second time in Great Destroyers and are shown to be evenly matched.
After Carolina and Washington become trapped by the Blues and Reds, Locus was the one who freed them. However, Carolina was less than happy to see him. She questioned his motives and asked if she knows the Blues and Reds. Upon telling the Freelancers of his new code she outright questions his ability to change considering his past actions, with him responding that they are not so innocent. He does show responsibility when dealing with her though, not willing to let her fight due to her weaker state.
Tucker[]
Similar to Grif and the other Reds and Blues, Locus once saw Tucker little more than a small obstacle. In Cloak and Dagger, Locus is shown to be condescending towards Tucker. However, following his redemption in Season 13, Locus is shown to have great trust in Tucker. After Washington gets shot in the neck in Desolation, Tucker urges Locus to allow him to join in taking Wash to the hospital. However, Locus denies; saying that the Reds and Blues need him as their leader.
Caboose[]
Like the others, Locus saw little threat from Caboose. Seeing him as a minor obstacle to his orders. However, after Chorus, His rescue of the Reds and Blues were met with animosity from them except Caboose. He was even willing to give his former enemy a hug upon being freed, much to Locus's dismay.
Other[]
Doyle[]
According to Doyle, Locus was instrumental in several victories of the Federal Army, and evidently, Locus also inspired the troops under Doyle's command, as he attempted to keep Locus at the capital during Out of the Frying Pan. Locus doesn't display much interaction beyond telling Doyle his plans, although Doyle appears to be genuinely terrified of him, as he describes Locus as a dog that he cannot control. After Doyle learns the truth of the space pirates' involvement in the civil war, he loses all trust in Locus.
Dr. Grey[]
While there aren’t many interactions between the two, it's clear that Locus doesn't care for Dr. Grey's life, though is polite to her to some extent. For example, when Grey tells Locus to leave Wash and the Reds alone in The Federal Army of Chorus Locus complies and leaves, only pausing to give Wash Freckles’ primary storage unit. Due to the fact that he was ordered to eliminate the people of Chorus, his politeness towards Dr. Grey can be seen as a ruse. Interestingly, while the Feds, and General Doyle for that matter, all fear Locus, Dr. Grey seems to be the only Fed brave enough to stand up to him.
Siris[]
The man who brought him and Felix together, as well as a former partner, Siris seemed to respect Locus more than Felix but would still berate him when he screwed up. Locus also had a great deal of respect for Siris and the two held a more professional relationship with each other. When Siris wished to leave in Consequences, in order to ensure his family's safety, Locus allowed him to do so, seeing it as the right, and logical, thing to do. Felix, however, threatened Siris if he departed.
Gabriel Lozano[]
An old target of his and Felix's, they went into his nightclub and kidnapped him for a 2 mill bounty and when his father Ruben removed his bounty from police records, held him for ransom. When his father refused to pay the ransom and threatened to kill them all, Locus shot Gabriel in the head and killed him.