Arthur Watts was a former Atlesian scientist that was disgraced due to a disastrous incident, the exact circumstances are currently unknown but from Watt's own words, General Ironwood seemed to have played a role in it.
Prior to him faking his death and being disgraced from the Atlesian military and scientific community, Arthur seemed to have been one of Atlas' leading scientific minds, as he himself stated to have invented and assisted in developing and creating the security systems of the Kingdom's two major cities Mantle and Atlas and was later seen having worked together with Pietro Polendina in its defensive military technology development.
However despite all of his service in developing the Kingdom, it was implied by Arthur himself that he never had much loyalty or care for Atlas in the first place, as he had created a secret back door into the Kingdom's security system for his personal use and later upon being disgraced from Atlas, Arthur showed little to no remorse by actively assisting and aligning with Salem in her plans to destroy the Kingdoms of Remnant and obtain the Relics, as seen when he assisted Cinder and her faction by creating a virus to infiltrate and control the Vytal Festival selection system's and take control of Atlas drones during the Fall of Beacon to attack Huntsmen and innocent civilians to further slander Atlas and began actively working on completely destroying the Kingdom together with his associate Tyrian Callows in order to advance Salem's agenda.
As seen in "Worthy", Watts himself was shown to deeply despise his former home kingdom and was delighted when Cinder offered to help him finish destroying it. Ironically, he would perish with the very kingdom he sought to destroy when he was left trapped in the burning command center just as Atlas crashed into Mantle and was immediately flooded soon after.
Arthur Watts was a member of Salem's group, having provided Cinder the virus to rig the Vytal festival and hijack the Altas drones. It was implied that he joined out of spite for Ironwood and Atlas. Notably, everyone, including Salem, addressed Watts by his title of doctor.
Not much was known of their relationship, but Watts was loyal and respectful toward her. Despite this, his faith in her was not absolute, as shown in "So That's How It Is", when he doubted Salem's claims that Cinder Fall was still alive. However, a stern look from Salem made him reconsider his disbelief. When Salem dealt with Watts, she boosted his ego to make him easier to manipulate.
In "The Enemy of Trust", after Watts got arrested and defeated by Ironwood, the disgraced scientist was first surprised when Salem and her army finally arrived in Atlas, but later turned into sadistic glee.
Later in "Midnight", Watts was able to successfully relay to Salem his success in gaining some level of control over the current Winter Maiden, causing Salem to be pleased with him and immediately sent Cinder to free him from Atlas and have him lead Cinder to Penny.
As seen in "Ultimatum", Arthur made it clear to Cinder that he worked solely for Salem and Cinder's own desires were irrelevant to him. Seeing how he explained that the virus he implanted Penny was solely for them to gain the Relic of Creation and not for Cinder to take the powers of the Maiden. Despite his loyalty, Salem had no qualms when leaving him to die in Atlas.
Despite their vastly different personalities, the two were arguably the most effective of Salem's teams. They were able to work amicably with each other, with Watts coming up with the plans, while Tyrian would carry them out.
When Salem asked Watts to have a new tail made for Tyrian following his loss to Ruby Rose, he took no issue with the request and set out to perform it.
Later, when he questioned Salem on Cinder still being alive, Tyrian immediately called him out, making him stammer for a moment before he regained his composure.
He was next seen calling for Tyrian in "Lost", saying it was time to disembark on their mission to Atlas.
In "A New Approach", when Watts secretly remotely communicated with Tyrian after they both arrived in Mantle, he reminded the concerned scorpion Faunus that finding a single hideout would draw suspicion and would be discovered by their enemies. Watts even reassured Tyrian that they would reaffirm their plan by staying mobile. He even mentioned the security code in Mantle hadn't been updated unlike the cyber security code in Atlas, to which Tyrian agreed.
In "Out in the Open", Watts and Tyrian listened to Robyn Hill and Ironwood's announcement, informing the people of Mantle of the two criminal's activities, enraging Tyrian. Watts calmed the serial killer down, having come up with a plan. He told Tyrian to keep the people's attention in Mantle, causing the latter to prompt how Watts wanted him to accomplish more panic than a Grimm invasion. Arthur rhetorically told Tyrian if anyone in Remnant could deliver that, it would be him. This gave Tyrian the idea to attack Robyn Hill later in the night.
After being captured, Watts still had the means to get in touch with Tyrian. In "Midnight", he contacted him to rely to Salem about his success in obtaining some control over the Winter Maiden.
Watts looked down on Cinder after she was thwarted by Ruby. He greatly enjoyed tormenting and angering her, especially since she was unable to respond following her injury. Given his comments, they apparently had a preexisting rivalry prior to her injury as well. Their mutual disdain of each other was likely the reason he didn't provide a prosthetic arm for Cinder, leaving Salem to replace it with a Shadow Hand.
In "Dread in the Air", he had a disappointed tone after discovering that Cinder's voice had recovered. In "A Perfect Storm", Watts worked with Cinder to pressure Raven Branwen into having Vernal use her Maiden powers to open the Relic of Knowledge's chamber. When she agreed to the bandit's demand for her brother's death, Watts warned Cinder of her intentions to get revenge on Ruby; however, she dismissed him and burned his hand in response.
His disbelief to Salem's claims in "So That's How It Is" implied that he believed that Cinder perished in Haven.
Later after his capture and imprisonment in Atlas and his report to Salem about his progress in gaining control of the current Winter Maiden, Salem ordered Cinder to go and rescue him from his cell and have him assist her in locating the Maiden and claim her powers to obtain the Relic.
As seen in "Dark", Cinder successfully located Watts and rescued him from his cell before escaping with him.
In "Ultimatum", their relationship took a turn for the worst. Cinder threatened to kill Watts by dropping him to his death after he revealed his virus was set to cause Penny to self destruct after she opened the vault. This made Cinder become enraged due to this scenario stopping her from retrieving the Maiden powers from Penny. She then impulsively grabbed Watts by the collar and dangled him from the building they were on in order to force her way. From there Cinder then began gloating about how she was going to kill Watts and retrieve the maiden powers for herself by taking advantage of Salem's temporary death to prioritize her own wants over their masters'. However Watts, instead of fearing for his life, ranted at Cinder about her numerous failures in achieving her goals and her own personal flaws of what lead to those failures. She then dragged him back from the ledge and cried. He did, however briefly, seem to regret it.
As seen in his rant, Arthur himself seemed to have deeper understanding of Cinder then what he initially let on. With him having implied that he knew some of Cinder's abusive past from how he stated that he knew that she suffered immensely that then led to her developing a massive sense of entitlement. He also understood her personality's serious flaw of thinking that she could simply get whatever she wanted through brute force and raw power.
In "Risk", Cinder was shown to now be cooperating with Watts as they began making their move and meeting up with Neo while intercepting Ironwood and Ruby's communication. The two appeared to respect each other more, as seen in "Worthy", where they along with Neo worked together to sabotage Ruby's plan to save Atlas and Mantle. As Cinder suggested that Watts could use his intellect to finish off Atlas, delighting the disgraced doctor. After taking control of Ironwood's base, she said to Watts that he deserved it.
Despite that, in "The Final Word", she left him behind in Atlas while also setting the control room on fire to cover her tracks after lying to Salem about the Relic of Knowledge, resulting in his death.
Watts treated both Emerald and Mercury with disdain, derisively calling them Cinder's "posse". He would take any and every opportunity to insult and belittle the duo whenever he could. Seeing how he agreed with Raven Branwen's snide insults and remarks on how the two of them were only children being manipulated and tricked by Cinder into following her, much to the duo's contempt.
At first, Watts was relieved to hear of Ozpin's death in "The Next Step". But when Hazel Rainart revealed he was taking the Relic to Atlas, Watts was not surprised, apparently knowing of Ozpin's ability to reincarnate. However, he also knew that Ozpin could get into Atlas, considering his connection to General James Ironwood.
Professor Lionheart was Salem's mole in Mistral and an important pawn in her targeting of Mistral. Arthur served as the representative of Salem to Lionheart. When he later met with Lionheart, he gave him a cup of tea.
Watts treated Lionheart with civility but also occasional playful condescension. However, he also had no concern for Lionheart when he was being strangled by Salem's Seer. Following Lionheart's death, Watts likely didn't care that Salem killed him.
As one of Ozpin's most trusted allies, Qrow was a primary target of Watts, who did not in any way underestimate the renowned Huntsman's strength and tenacity in combat. Due to this, Watts was extremely wary of Qrow's abilities and had no desire to engage him head-on.
The two had few interactions, but when the news of Ozpin's return reached Salem, Watts and Tyrian were ordered to deal with General Ironwood so he didn't undermine their plans for Vacuo.
In Volume 7, it's revealed that Watts had an antagonistic professional history with Ironwood. He claimed that the General had played a role in getting him disgraced in the first place. Ironwood personally considered Watts "a pain in the ass" and likely took issue with Watts' arrogance regarding his intellect and scientific contributions to the military.
During the chaos in Mantle when Watts flew up to Amity Tower to sabotage, he only found it unfinished. He was then locked inside the Colosseum and confronted by Ironwood, revealing Amity to also have been a trap. Watts hacked into the Colosseum and activated the Anti-Gravity biome before pulling out his revolver and proclaimed that he won't go down without a fight, showing that he wasn't afraid to fight against the Headmaster of Atlas Academy.
During their fight, Watts claimed Ironwood never appreciated his genius, calling James out for standing atop his own intellect and using it to "call himself a giant". Ironwood disagreed, saying he gave Watts everything he could have wanted, to which Watts retaliated by saying that he chose Pietro over him. After Arthur was defeated, Ironwood told him that he'd sacrifice everything to stop Salem. Watts spitted at him, telling James that he hoped Ironwood did.
Later, Ironwood forced Watts to work under him at gunpoint in order to re-secure Penny. Watts implied that Ironwood had used physical force to get him to work with the group. James lacked trust in Watts, and was easily angered by the scientist's snarky attitude. Later on, when having Watts hack Penny and being angered when supposedly she didn't respond, Watt's was able to trick Ironwood into throwing his scroll. Unaware of the doctor taking it without realization, and once Watts escaped thanks to Cinder, he became upset while claiming that either Watts was incompotent for not being able to hack Penny, or he had betrayed him once more.
Not much was known to Watt's relationship with Jacques. But in "Pomp and Circumstance" it was shown when Watts made an unexpected visit in the Schnee Manor, Jacques was shocked to see him again, believing the disgraced scientist was dead. Watts dismissed the notion, claiming that was his intent the whole time.
Watts also seemed to be aware of Jacques' issue with General Ironwood and made a dubious offer in order to aid his Dust Company and for Jacques to win the election.
Though after Jacques gained the council seat, Watts shut down the heating generators in Mantle using the newly given high access clearance afforded to Jacques as a councilman. Despite knowing full well that his deal with Jacques would be revealed and Jacques would then be held accountable for it, Watts had only considered Jacques as a pawn to further his and Salem's goals.
After they were both arrested, Jacques blamed Watts for getting them in jail with Watts nonchalantly agreeing with him.
After Watts escaped from prison and took control of the command center, he freed Ironwood from his cell, which led to Jacques death as the former shot him with his cannon.
In "Pomp and Circumstance", there wasn't very much interactions shown between Watts and Whitley, except that Whitley was nervous and suspicious of the disgraced scientist. Watts complimented to the young boy that he resembled so very much of his father in a "creepily" way to add.
Upon finding and meeting Raven Branwen in "A Perfect Storm", Watts was professional in front of her but pressured her into cooperating with Salem. However, he disagreed with her terms for luring her brother into his death because of the risks of exposure and putting the Kingdom on high alert.
Before Watts had faked his own death and joined Salem, he used to work with a team consisting of Pietro and three unnamed scientists. During their time, other scientists thought Pietro's rivalry with Watts was overshadowed by their friendship, only to be proven to be wrong. After Watts faked his death, Pietro was supposedly shattered by the event.
In "Worst Case Scenario", Pietro was seen having kept an image of this team, where Watts was seen glaring at Polendina.
In "Gravity", it was revealed that Watts had a strained relationship towards Pietro, hating him for being chosen by Ironwood over him and even calling him a "fat imbecile" out of spite.
Later, he helped Ironwood hack his daughter Penny due to being threatened and showed joy in harming Pietro's daughter.
Due to Penny being the creation of his rival Pietro, Watts was shown to have a level of animosity for Penny and like his associates, considered her nothing more than a machine and not an actual person. Watts himself was never able to wrap his head around the idea of a Soul transfer, and he greatly underestimated Penny's cognitive capabilites because of this.
As seen during the events of Volume 8, Watts was forcibly "convinced" by General Ironwood to help him obtain control of Penny in order to have access to Vault containing the Relic of Creation for his plan to move Atlas. With Watts being given extensive knowledge on Penny's blueprints and system data in order to hack into her. This eventually led him to gaining crucial information on how Penny's body and mind operates and leading him to successfully devise a method to take control of her.
As seen in "Amity", Watts was able to successfully hack into Penny's A.I. and compelled her to possess the strong drive to go back to Atlas and access the Vault. This however ended up short circuiting Penny's systems instead. As seen in "War", despite this, Watts was shown to still be confident that he could control her and fed this information back to Salem.
Later, in "Dark", it was revealed that Watts had ordered Penny to open the Vault and then self-terminate, showing that he had no further use for her afterwards.
- Volume 5 Directors' Commentary Chapter 2
- RWBY Volume 8 Directors' and Writers' Commentary Chapter 13
- RWBY Volume 8 Directors' and Writers' Commentary Chapter 13
- RWBY: Amity Arena Watts character bio
- RWBY Volume 8 Directors' and Writers' Commentary Chapter 5