Roman was a key member of Cinder's group. Virtually all of his crimes and actions were made in pursuit of the goals of the group. Up until his capture, he appeared to be one of the most active agents of their cause, orchestrating numerous Dust robberies, financing and equipping their allies, the White Fang, and masterminding the scheme to bring the Grimm to Vale.
Despite all this, he appeared to be a mere functionary. He was kept in the dark about the group's overall goals and made to simply follow orders, though given some leeway as to how to execute them. It's heavily implied Cinder used her Maiden powers to strong arm him; given Roman shut up immediately upon her overhearing him threaten Mercury and Emerald.
In his last fight with Ruby, Roman stated that he couldn't risk losing what he had by going against Cinder's plans and knew it was a losing bet; suggesting he at least had an inkling that Cinder worked for someone much worse.
Roman worked alongside the terrorist group on Cinder Fall's orders. Despite having the authority to order them around, he did not show much enthusiasm for the relationship, repeatedly insulting and discriminating against the members based on their Faunus heritage.
In "Painting the Town...", Roman addressed a large number of White Fang recruits and soldiers at the White Fang Faction Meeting. Whilst many Faunus in attendance had misgivings about working with a Human, he did manage to win them over to his side, claiming that they share a common goal and enemy. The White Fang Lieutenant also referred to Roman as "a very special comrade" and assured the crowd that he was "the key to obtaining what we have fought for for so long". However, Roman harbored a strong distaste for the White Fang rank-and-file, referring to them as animals in "No Brakes".
When Roman was 18 in Lower Mistral, he stole from one of the patrons that frequented one of Spider's bars and was caught by two members of the syndicate. After defeating them, he was found by a small army of syndicate members a few days later and taken to see Lil' Miss Malachite, the leader of the syndicate.
After she saw potential in Roman, she offered him a choice to join her syndicate. Eventually, Roman accepted and joined Spider while becoming the second-in-command of the organization. Because of this, he was sometimes given important jobs such as looking after Lil' Miss's daughters Melanie Malachite and Miltia Malachite.
As time went on however, Roman became more ambitious and started going against Spider's policies. Due to this, Lil' Miss eventually ordered Roman to be assassinated. However, Roman managed to thwart the attempt on his life and defected from Spider to become independent in Vale. After meeting Neopolitan, the two of them thwarted Spider's plan to take over Vale's criminal underworld by exposing their ally Lady Browning's Preparatory Academy For Girls for being a school that secretly trained spies and assassins for criminal organizations.
Roman worked under Cinder's orders. She assisted him in the escape stage of his failed robbery in "Ruby Rose". Although they worked together, they did not have a very good relationship on a personal level. Cinder routinely threatened and coerced him into working for her, and he accordingly tended to act uneasy and nervous around her. For example, when he complained about her forcing him to work with White Fang, she coldly responded that they required his "cooperation", punctuating this with the clear threat of igniting a fireball in her hand. Torchwick regarded Cinder to be very powerful and was more than a bit intimidated by her.
When he complained about being kept in the dark about Cinder's overarching plans, Cinder merely informed him that he would "know what he needs to know, when he needs to know it." Nonetheless, he continued to follow Cinder's orders, albeit unwillingly. Roman also refused to out Cinder as the mastermind of the plan to General James Ironwood when he was captured and interrogated, though whether this was out of loyalty to Cinder, fear or something else is unclear. He did, however, tell Ruby Rose in "Heroes and Monsters" that he could not stop the people who hired him and that he could not afford to lose.
Roman worked with Emerald and Mercury due to his connection with Cinder Fall, though he clearly looked down on them, referring to them as "the kids". He treated them with condescension and hostility, which they readily reciprocated. He also briefly threatened them, but he was cut short by Cinder.
Neopolitan was Roman Torchwick’s partner, ally, and friend. Neopolitan was Roman’s equal partner in crime with romantic implications.
Torchwick and Neo had a good working relationship, as seen when she came to his aid after he lost the battle against Team RWBY in "Painting the Town...". Neo is confirmed to be the only person so far Torchwick did not hold in contempt or disdain.
In Heroes and Monsters, he reacted emotionally when Neo was blown away from the airship by screaming her name in horror and reaching out. Afterwards, he brutally beats Ruby Rose with his cane in an emotional response.
On the DVD cast commentaries, series writer Miles Luna speculated that Neo would be even more dangerous if she did not look up to Torchwick as much, and compared their relationship to that of Harley Quinn and the Joker from Batman. Lindsay Jones also compares their relationship to that of a daughter and father, which Miles agreed with. On November 7th, 2020, this was directly contracted in a fan interview by Miles stating they do not have a familial relationship whatsoever. Roman Holiday canonically refutes the abusive Harley and Joker implication, as well as the father daughter comparisons.
The closeness of their relationship is shown most significantly in RWBY: Roman Holiday and in the show after Roman’s death. There are many points in the book where Roman feels conflicted on being involved with Neo maybe, as though he is dragging her into a life of crime. However, Neo fervently showed her interest in engaging in criminal activity which reassured that he was not negatively impacting her.
Despite barely surviving the Battle of Beacon herself, Neo went out of her way to avenge Roman, as seen when she tracked down Cinder Fall in Mistral to kill her. During the confrontation, Neo clearly showed that she greatly missed and grieved for him and kept his signature hat in memory of him.
RWBY: Amity Arena implied the possibility of romantic feelings between Roman and Neo by releasing Roman and Neo themed Valentines Day content (matching Valentine skins, "Will you be our Dum-Dum?" message in the inbox, accompanying the romantic-coded “Dum-Dum”player title.) Social media managers for the game, such as on Instagram and Twitter, as well as official artists, commented their own support.
In a fan interview on August 20, 2020, Miles Luna claimed that the RWBY production has differing ideas of what exactly Roman and Neo's relationship was like, and they have toyed around with a lot of ideas, but the exact specifications of their relationships has “never been nailed down.” Miles also affirmed that "there is definitely a love there". The nature of their relationship is later canonically clarified in Roman Holiday. The two share a close, equal partnership with comparisons to being each other’s “home.” In addition, ''Roman Holiday'' contains several amorous interactions, such as emotional hugs, the two getting flustered over each other, and a kiss at the end of the book.
Lil' Miss Malachite first met Roman when he was 18 and stole from one of the patrons of Spider's bars and had her syndicate bring him to her. After she saw potential in him, she offered him a choice to join her syndicate and he eventually accepted with him becoming her second-in-command in the organization. While he served at this position, he was given important jobs by her such as guarding her daughters Melanie and Miltia Malachite.
As time went on however, Roman became more ambitious and eventually started going against Spider's policies. Because of this, Lil' Miss ordered for Roman to be assassinated for going against her. However, Roman was able to thwart the attempt on his life and defected from Spider to become independent in Vale. Later, he thwarted Lil' Miss's attempt to take over Vale's criminal underworld with help from Neopolitan and exposed her ally Lady Browning's in the process.
It is currently unknown if Lil' Miss knows that Roman died during the Fall of Beacon.
Ruby was one of Roman's enemies. He continuously called her "Red". She first met him in the shop From Dust Till Dawn, which he happened to be robbing at the time. She prevented him from robbing it and chased after him until he escaped with Cinder in a Bullhead.
The two met again in "Black and White", where Roman instantly remembered her. He then successfully landed a shot on Ruby due to her being distracted. Roman also clearly demonstrated some dislike for Ruby due to her foiling of his robbery a few months back. They confronted each other in "Painting the Town...", where Ruby, with the aid of the rest of her team, once again foiled his plans, destroying his Atlesian Paladin-290 mech.
Roman's animosity toward Ruby was further seen in "No Brakes", where he delighted in her torment after she is captured, before attempting to kill her along with other members of the White Fang. He was also very put off by her persistence in "Heroes and Monsters", expressing audible annoyance at her arrival. He became much more angry and hostile toward Ruby after she sent Neo sailing off the airship.
Due to Roman's discriminatory remarks toward various White Fang members, Blake showed a particular hostility toward him, to the point where she rushed in and puts her blade to his throat. This first encounter appeared to have had an effect on Blake, who obsessively turned it into her personal mission to apprehend Torchwick and the White Fang, to the detriment of her own health.
The two met again in "No Brakes", where Roman teased and taunted her, saying "We have to stop meeting like this, people are gonna talk", which enraged Blake. They engaged in combat once more, but he was bested by Blake due to her use of combining Weiss Schnee's Dust with her Semblance. After he taunted her to join him, she refused and knocked him out.
Although having interacted only through battle, Roman addressed her as Ice Queen, possibly due to her use of ice during their fight, much to her annoyance. It is unknown if he was aware of her status as heiress to the Schnee Dust Company or that she is part of the Schnee family.
Roman fought once with Yang during the battle with Team RWBY. He used the Paladin to deliver a hard blow to her body, that potentially could have done more damage if not for Yang's Aura. Yang was the one who definitively destroyed the Paladin, breaking it into pieces around Roman and winning the fight.
Roman fought Sun twice. The first time was on the docks while stealing a shipment of dust. Sun dropped a banana peel on his head, and when Roman dislodged it and looked up, Sun jumped on his face. The two fought directly after Sun defeated the White Fang members and Blake lost the upper hand in a one-on-one with Roman. The fight was interrupted by the arrival of Ruby Rose and Penny Polendina.
It was memorable enough to Roman for him to recognize both Sun and Blake in their White Fang new recruit masks amongst the crowd at a White Fang meeting. This led to Roman's second fight with Sun. Chasing both him and Blake inside an Atlesian Paladin-290, Roman was subsequently attacked by the rest of Team RWBY as well as Neptune Vasilias. Sun landed an ineffective strike against the robot using his Semblance. He was removed from the fight when Roman threw Neptune off the Paladin and into Sun, causing them both to fall off the raised motorway.
Roman briefly fought with Neptune once from inside an Atlesian Paladin-290. An alert made him aware of Neptune and Yang approaching on a motorcycle behind him, and he immediately knocked cars backward toward them. They evaded the vehicles, and Neptune fired his gun at the Paladin, striking three out of four hits. Neptune then transformed his weapon from a gun into a trident and leaped on top of the Paladin, striking it. Roman spun enough to dislodge Neptune, incidentally knocking Neptune into Sun and removing them both from the fight.
In the "Yellow" Trailer, Roman was seen speaking to Junior. Junior revealed in "Painting the Town..." that Roman hired some of his henchmen for a job from which none of them returned. Junior did not seem to know much about Roman and claimed not to have had any contact with him since.
Upon capture for leading Grimm to Vale via Mountain Glenn's subway, Torchwick was handed over to General James Ironwood of the Atlesian military. Ironwood was given custody of him for as long as he saw fit, and he imprisoned Torchwick on his airship. Ironwood attempted to get information out of him, but Torchwick refused to cooperate, lying and stating that he was the mastermind behind the entire plot.
Ruby interrupted Roman's fight with Blake and Sun, Penny by her side. When Ruby was distracted by Penny, Roman took advantage and shot Ruby backward. Penny was motivated by this to jump into the fight, and she attacked Roman's White Fang associates with several floating swords. Her intimidating and effective methods caused Roman to decide to flee, commenting that the kids just kept getting weirder.