Roman was a key member of Cinder's group. Virtually all of his crimes and actions were made pursuant to 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.
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 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".
Roman worked under Cinder. She assists 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 a little scared of 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 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.
Torchwick and Neo had a good working relationship, as seen when she came to his aid after he lost the battle against Team RWBY. Neo appeared to be the only person Torchwick did not react to with contempt and disdain.
In "Heroes and Monsters", he reacted emotionally when Neo was blown away from the airship and was more enraged toward Ruby afterward.
On the DVD cast commentaries, series writer Miles Luna speculated that Neo would be even more dangerous if she didn't 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.
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 because she foiled 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 combing 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 Semblance. Yang was the one who definitively destroyed the Paladin, breaking it into pieces around Roman and winning the fight.
Roman fought with 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 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.