In addition to being Azmodeus' and Cicily's son and Holland's older brother, he is also the brother-in-law of Talho Yūki, and the paternal uncle of an unnamed Novak child.
Dewey Novak wears a colonel style outfit that is white with sky blue accents, and various gold designs. His skin is pale, in color, and he has gray hair, with bluish-gray eyes, like his brother Holland.
Dewey Novak is the primary antagonist of Eureka Seven. He is a manipulative and sociopath man who commits several acts of mass murder in pursuit of his goals. Through his combined talents of charisma and intelligence, he seizes control of the United Federation and begins a murderous campaign to rid the world of the Scub Coral.
A former lieutenant colonel and Holland Novak's older brother, Colonel Dewey was imprisoned as punishment for Holland and the SOF's desertion, for which they believed him to be responsible. This is also apparently part of the attempt to shut down the remnants of Adroc Thurston's project. Later (and presumably under the auspices of Coda), Dewey is released and promoted to the rank of colonel, taking Dominic Sorel and Anemone under his command. In a complicated and carefully calculated plan, he undermines the public's faith in the Sage Council and overthrows them.
According to Dewey, the Novak family existed to calm the planet. The ritual to do so involved an act of patricide, an act that Dewey assumed was reserved for him.
However, when he was only 7 years old, his mother died during his little brother's birth, Holland, and the title of "Sacrificial King" was automatically passed on to his newborn brother.
Despite resenting Holland, their father lavished him with attention and affection, often ignoring Dewey, who was left with a deep hatred towards his brother. With his ambitions of becoming the Novak family's next patriarch ruined, Dewey murders his father in cold blood only to have the planet "reject" the ritual and his succession. With no legitimate heir, the other noble families seize the Novak family's assets leaving Dewey and Holland orphaned and homeless. As a result, Dewey bears a pathological hatred for his brother as well as the planet for denying him what he believed to be his birthright. However, since the only account of this event is given by Dewey to Anemone, parts of it might actually be a delusion he created. At the end of the series, Holland admits that he did not know how Dewey's madness came to be.
During their teenage and early adult years, Dewey and Holland were part of a ref board group and traveled around the world. However, Dewey joined the military and quickly rose to the title lieutenant-colonel, with Holland soon following in his brother's footsteps by becoming an ace unit soldier. About ten years prior to the series beginning, Dewey was present when Adroc Thurston and Eureka unleashed the Seven Swell Phenomenon. He then ordered that Eureka be put in Holland's care to be trained as a child soldier shortly after Adroc's "death" and assigned them to the SOF. He did this because he wanted to use Eureka and the Nirvash for his own benefit. Three years earlier, he ordered the SOF to invade Ciudades del Cielo and eliminate all the Vodarac residents by falsely claiming they were terrorists for protecting the Coralians. Once Holland learned the truth and fled the military, Dewey was blamed for his brother's defection by the Sage Council and sent to prison.
After spending three years in prison, the Sage Council, led by Coda, ordered him released and promoted him to colonel. Dewey led a campaign to destroy the Scub Coral by, with the Sage Council's awareness, committing multiple acts of mass murder. As part of his campaign, he takes Anemone and Dominic under his wing, making Anemone the pilot of theEND and promoting Dominic as second lieutenant. His strategy is to attack the Scub Coral into unleashing the Antibodies and win public favor from the human population, and then activate the Oratorio Number 8 to locate and destroy the Scub Command Cluster. This leads the Gekkostate to conclude that Dewey wants to activate the Limit of Questions to not only eliminate the Scub Coral but the entire world. For seasons 1 and 2, he rarely interacts with the Gekkostate, often watching from afar in battles and sending Anemone to fight Renton and Eureka. He initially does not take his war with the Gekkostate seriously due to his belief that they have yet to find a partner for Eureka to save the world (as in order to unite the humans and Scub Coral, Eureka must declare a human as her partner). He also creates the Ageha Squad, which consist of five young girls who had been victims of ethnic cleansing and are willing to do anything Dewey says.
In season 3, Dewey is confronted by Norb, who had recently came out of hiding after 3 years. Norb demanded for Dewey to stop with his mission on destroying the world, but Dewey refuses to listen and mocks Norb for his Vodarac prophecy that the humans and Scub Coral can be united. However, Dewey knew that the Gekkostate was on their way to retrieve Norb to help them get over the Great Wall, and Dewey was no concerned. When he and Holland finally confronted each other after three years, he mocked Holland for not finding a partner for Eureka and always being behind him, and he can have Norb for all he cared. But once he saw Eureka and Renton piloting the Nirvash together, he realized that Holland was indeed catching up to him and was worried about Renton and Eureka actually fulfilling Norb's prophecy of uniting the two species. He then set out to win the public's favor by unleashing the Antibodies and causing them to attack populated cities, and then having Anemone defeat them. He also painted the Gekkostate as an enemy by claiming they were protecting the Coralians. However, needing the final installment of his plan, he sought full power and authority of the Sage Council by murdering two of the sages and spared Coda, who was never against him. She ultimately awarded him all the control over the military to build the Oratorio Number 8, which gathers solar energy from outer space and will destroy its target, which is to be the Scub Command Center.
As the Gekkostate, with the help of Norb and Dr. Bear, investigate Dewey's motives, they speculate that Dewey bears a deep hatred for the Scub Coral and also focus on his efforts on destroying it, which may stem from the planet rejecting him performing the ritual. Due to Anemone's inability to defeat Renton and Eureka with their Nirvash, Dewey starts to lose interest in her and starts searching for a replacement for theEND. He orders the military to attack the Gekkostate and Anemone to attack Renton and Eureka at the Vodarac Shrine and was unconcerned when he was told that Renton and Eureka made it past the Great Wall while Anemone failed. He later takes anemone to a New Years party, where he tells her about his childhood, his hatred towards Holland and the Scub Coral, and how he feels that he was deprived of becoming the Sacrifical King. Anemone thinks he is exaggerating but Dewey doesn't say anything more and simply returns to his ship so that Dominic can look for her replacement. Shortly after, he locates the Scub Command Cluster, activates the Oratorio Number 8 into shooting a gap through the Scub Coral, and destroys the Command Cluster. He and his crew enter the gap after the Command Cluster's destruction and orders the Ageha Crew to bomb the Nirvash with Renton, Eureka, and the kids inside. Then, Holland confronted him with the his 303 LFO and then invaded Dewey's ship. In their battle, Holland shouted that he is destroying the world and Dewey admits this but feels he is justified. Dewey explains that he had thought the planet could be redeemed but now sees the planet as beyond redemption due to being absorbed by the Scub Coral. In an unexpected twist, Dewey revealed to his brother that he secretly had a Compac Drive embedded in his chest, much like Norb. His Compac Drive, however, is more like a dead man's switch which he claims binds him to the Earth itself. He states that the entire world will die with him (this is significant as nobody else has been able to meld with a Compac Drive without dying, as in the case of saints born from the Vodarac). By declaring that his death will bring forth a new world, Dewey shoots himself in the head to set his plan of planetary genocide in motion. Holland is found moments later by Talho with tears in is eyes and confessed that he was "too late to save Dewey", showing a rare moment of sympathy and love for his brother.
However, his death activated the collars that Eureka and Anemone always wore; Anemone was able to take hers off and it failed to work properly, and Eureka's caused her to turn into a black void. After studying the collars, everyone learned that Dewey foresaw that Eureka or Anemone would become the replacement Command Cluster in the event of the existing Command Cluster's destruction, and that Limit of Questions wouldn't be activated so easily. As a result, he had special collars attached to both girls that would activate a system that would relay a self-destruct sequence within the Scub Coral and destroy it. They speculated that Dewey never really wanted to activate the Limit of Questions and his main intent was to exterminate the Scub Coral more than the entire world. Despite these revelations, Holland feels guilt for not being able to save Dewey from his madness and vows he will shoulder Dewey's "burden", even if it takes the rest of his life. In the end, Dewey completely underestimated Renton Thurston as he interfered his plot and rescued Eureka.
- Despite being the main antagonist, Dewey never had any direct confrontations with the main protagonists, Eureka and Renton, except for a brief meeting when they retrieved Norb.
- Dewey always believed that Eureka would never find her partner, and thus, was less concerned with his conflict with the Gekkostate. But after seeing her and Renton pilot Nirvash together in episode 35 and realizing he had been wrong, he set out to eliminate the couple from stopping his plot.
- In the manga, Dewey was so opposed to Adroc's theory of forming a co-existence with the Coralians that he murdered him and covered it up by blaming the Vodarac people, and fooled Holland into leading the SOF into the Ciudades del Cielo massacre.
- Also in the manga, he doesn't insert a Compac Drive into his chest because he knew the Coralians' intentions were to destroy the human race and he allowed this to occur in order to bring forth a "new world". Instead of committing suicide, Dewey was killed by Holland in a gun fight.
- It was Dewey's efforts to destroy the Scub Coral, and potentially the world, that caused Holland to personally set out to stop him by thinking he can partner with Eureka and unite the humans and Scub Coral to overthrow Dewey. Because of this, Dewey is indirectly responsible for Holland's initial indifference towards the crew, his obsession with Eureka, and grudge towards Renton in the beginning.