- "Your articles are honest and smart. I could never write the way you write."
"You have two Pulitzers."
- "It's not from the writing. It's from the story. I have craft, you have art."
- —William Dey and Kara Danvers[src]
William "Will" Dey was a renowned reporter, formerly of The Times, National City, and a reporter of CatCo Worldwide Media. He was at odds with his co-worker Kara Danvers as he was undercover to learn more about Andrea Rojas and her role in the death of his best friend Russell Rogers in the original multiverse. In the new multiverse, Will is always Kara's friend and renounces to his revenge. He was murdered by Lex Luthor trying to protect Esme and Andrea from him and Nyxly., and the Daily Mail. He was a resident of
At various points in time, William started working as a reporter for The Times, Le Monde, and The Mail; he eventually resigned from them all. At some point, he was renowned for his article on eminent domain in Hartlepool.
William was the best friend of Russell Rogers. Russel was dating Andrea Rojas, and expressed his concerns about her family when they once met at a bar. After becoming Rip Roar and while leaving his house, Russel was confronted by William. William became convinced the Andrea Rojas and Rip Roar were involved in Russell's death, and begun to pursue this to the point of obsession.
Working at CatCo
In October 2019, William started working at CatCo Worldwide Media. Andrea later introduced William to Pulitzer Prize-winning reporter Kara Danvers, who didn't make a good first impression for him due to her mispronunciation of the town name Hartlepool. Andrea consulted Kara on William rewriting her article on the governor's proposed water tax, an action Kara took offensively as it had all the necessary facts. William explained that the piece was filled with too much unnecessary information and reasoned that every piece has inherent bias, which was the complete opposite of what Kara expected him to say, due to his reputation from when he was still working with The Times of London; William clarified his works were of their respective natures solely due to the orders of his former superiors. In her suppressed outrage, Kara cleared up what she will and will not tolerate concerning her works, to both Andrea and William's surprise and reaffirmation of her resolution.
William sees Kara leaving CatCo and asks the NSA for help to follow her. William follows her to a sewer and finds Supergirl and a White Martian. Spergirl then helps him to escape. William wound up keeping in touch with her article and Andrea reassigns her to duplicate altering. Kara stands up to William and trench the work on him.
At a nightclub, William approached Niles Jarrod and once again demanded that he reconsider working together. The man again declined, before leaving with an blonde woman. The next day at work, Andrea Rojas wanted a "sparkly" story of murder. When coming across billionaire, Niles Jarrod who died at a club, she waved it off as nothing important, and William supported her in this. Kara and William found themselves in a verbal altercation. William told the room he had already looked into it, and there is nothing there. Afterwards, Kara confronted William outside about why he was lying. He blew her off, calling her paranoid. Later, William was sitting on a park bench. A man passed him a rolled-up newspaper with money inside of it.
William later goes to Mexico City. There, he looks for Elena Torres but apparently she was killed. So, William gets into a car driven by Sergio Ramos. William enters a room, and Kara quickly switches outfits. William urges Kara to leave, but Kara demands to know what's going on. William reveals that he is undercover to investigate Andrea. Kara asks for the truth, and William reveals that he helped Elena fake her death because she thought "they" were onto her and that he needed to keep her safe, and that Sergio Ramos is actually a member of Interpol, and is just undercover in Intergang, and that he helped get Elena out. He is staying silent about the Rojases because he has no proof that directly connects them to a criminal conspiracy he claims is bigger than Al Capone; he took the job at CatCo to get closer to Andrea and get into her inner circle. He states that how he acted at CatCo was simply an act, and he thinks that Kara's writing is actually really good.
Kara texts William to meet her for coffee across the street. While at the coffee bar she convinces him to let her help, while adding if he does, he will have access to the government base her sister works at. He reluctantly agrees, and they are both allowed temporary passes on the D.E.O. premise. Alex allows them in for her interrogation of Breathtaker, but William loses his cool and Alex kicks him out. Outside he confesses he has lost friends to the cause.
William takes it upon herself to break into her boss’ office to look for clues but is almost immediately stopped when Kara arrives to do the exact same thing. William is unable to crack her computer, that Kara is able to find a secret hidden box. Inside is a photo of Andrea and Russell Rogers along with some jewelry and some other objects. Will admits the reason he has been so obsessed with uncovering the Rojas Family, is because two years ago his best friend was dating Andrea. The day before they met, his house was broken into and he never saw Russell Rogers again. Kara tried to console him.
Later, Kara goes to William's apartment to give him the unfortunate news. Rip Roar is actually his missing friend Russell Rogers and it would appear that the Rojas Family is completely innocent, as the disaster would have lost them billions.
William was called to the D.E.O. to see Russell. He said that his friend would never be able to do that. When the Shadow attacked the facility, Supergirl saved him. The next day, Kara told William that the shadow helped Russell to escape.
During the Anti-Monitor Crisis, William as well as everyone in the multiverse except for the seven Paragons, was killed in an antimatter wave by the Anti-Monitor on December 10, 2019, only to be restored a month later, after the Paragons and the Spectre created a new universe.
William's life appears to remain the same, after the creation of Earth-Prime. He still works as a reporter for CatCo, determined to expose the truth. He is motivated by the fact that his best friend, Russell Rogers, died under suspicious circumstances after turning down a deal from Lex Luthor, leading William to believe Lex is not the good guy he claims. However, in this timeline he joined CatCo to get close to Lena Luthor instead of Andrea Rojas.
William and Kara accompany each other to a toy convention where they run into Lex, much to his own seething anger. After some hostile questioning about a possible murder, Lex removes himself for a word with Kara. Back in the office his conversation with Kara about his pending theories on Lex are interrupted when their boss Andrea calls for them. The next day he reveals photos of Lex at Fort Harrison paying off security guards, they decide to work together. After, Kara invites him to her apartment along with the rest of her friends for drinking and games. Kara later invites him to karaoke night, and after admitting his favorite song to karaoke to is ‘Africa’, Kara’s sister convinced them to sing a duet together. She is soon called away by her sister for help with their sick grandmother. Days later she finds him during the temporary blackout at the office. After presenting Kara with a puzzle for her grandma, and asking her out, Kara politely turns William's romantic advances down. He thanked her for her honesty, and promises there are no hard feelings.
Learning about Eve
Before work, William brings Kara and Nia coffee. He is assigned to cover his boss' campaign trail for Obsidian Platinum despite her being attacked in the elevator earlier. He agrees, and runs into Supergirl who is Andrea's bodyguard for the day. While talking about his co-worker Kara that he admires, they are interrupted when Andrea is attacked for a second time. 
The next day, William meets with Kelly Olsen and discuss Alex and Kara's loss of their father. He confirms Kara has already returned home for the funeral, and Kelly admits Alex Danvers is angry and refuses to go. Later William begins looking into trial users for Obsidian North lenses. The mass majority of whom are simply binge watching their existence. However approximately 50 names are all unresponsive and located at the same address. Though William goes to their location, Margot Morrison makes them invisible to him; he only leaves with a hospital bracelet. William was present during the arrival of Lex Luthor and Gemma Cooper at Obsidian Tech.
The next day, he and Kelly research the manifesto video that was left behind when Lex was forced to kill Margot to save her kidnapping victims. They learn that it was Eve Teschmacher using an image inducer. When he takes his findings to Andrea, she harshly dismisses him and tells him that he needs to stop trying to delay the launch of her work. William decides to work solo to keep Kelly from further trouble.
William was following Eve when she stepped into an alley; as he looked through the alley, a black sack was placed over his head. At gunpoint, William was confronted by Eve, who explained that she worked for Lex because her mother is being threatened; William promised that if he was released he would help her to expose Lex and free Eve Teschmacher's mother. Eve did not believe him and shot him anyway; just then, Supergirl and Lena Luthor arrived. Supergirl cauterized the gunshot wound that had totally gone through William's shoulder. He worried about the welfare of Kara Danvers, but Lena assured him that she knew that Kara was safe.
Trial of Lex Luthor
William still has a broken arm. He was present when Andrea said that CatCo's problems are solved when her father "bought the shares". Nia said that Kara was on an assignment with Cat Grant and William was upset that she didn't tell him in person.
William and Nia were assigned to cover the trial of Lex Luthor as he was charged with crimes against humanity; William and Nia both knew that they could not even enter the courtroom because the security there was so restrictive. William watched Lex's trial at CatCo; Lex was acquitted. William became disillusioned and began to lose hope; though Nia tired to encourage him, William stayed silent, listening and walking away.
Covering the Superfriends
After Esme was revealed to be a bearer of the love totem, William Dey tried to stop Lex Luthor and Nyxlygsptlnz from tracking Esme. When they left, he turned down the camera of his cellphone to film further. Lex Luthor returned to shoot him since the latter thought he leaked his diary, while he revealed that he hacked Lena's search in the Lexosuit so the results on Esme would be delayed. With his last breath, he sent the video to Andrea.
Supergirl and the rest of the Superfriends found him dead.
William at first appeared to act highly of himself and look down on others but in reality, this was an act. He started as an arrogant jerk. He sounded like Andrea's lapdog, with his criticizing of Kara's work. It was eventually revealed he is actually a nice guy and he cares about people. He is working undercover for the London Times and believes that Andrea and her family are criminals. He even volunteers at soup kitchens to feed homeless people during his free time. It is the main reason why he workes at CatCo and treated Kara badly because he wants to take down Andrea and her family, and avenge the "death" of his best friend. So, he became Kara's new ally.
He is seen to be a brave individual, choosing not to reveal to Lex that it was in fact Andrea who gained access to Lex's journal, knowing that it would put a target on Andrea's back if he spilled; leading to Dey taking the secret to the grave.
- Expert investigator: William has earned a big reputation working with The Times, Le Monde, and The Mail. Being well renowned for his stories. Even being able to track down Kara Danvers while she was Supergirl by way of guidance provided by a tech-savvy contact. He has excellent perception and empathy towards a person's nature. Despite being held at gunpoint by Eve Teschmacher, he correctly deduced that she was not truly a villain, but rather being forced to commit such actions under threat of her mother's life.
- Skilled hand-to-hand combatant: William was able to swiftly overpower and defeat several people at once.
Behind the scenes
- William is the third main character on who doesn't have a comics counterpart, after Alex Danvers and Kelly Olsen.
- Not counting Reign, William is the first and only main character of the show to die.