Michael C. Hall returns from the dead in Dexter: Resurrection in the aftermath of Dexter: New Blood, in which he is near-fatally shot by his son, Harrison Morgan (Jack Alcott). After miraculously recovering, he goes deeper into the murky underworld of murders in New York City, courtesy of Ronald "Red" Schmidt, who introduces Dexter to a dinner party for serial killers.
With four of the ten episodes released so far, the crime drama adds another piece to Dexter's morally ambiguous lore. Although most serial killers are yet to be seen in action, the show introduces some of the scariest personalities the franchise has seen in a while. The fact that they all know each other makes them all the more powerful.
Deeply troubled, exceptionally skilled, and fueled by vengeance, these serial killers could make Dexter: Resurrection have one of the most interesting plotlines in the Dexter universe.
Disclaimer: All opinions in this article belong to the writer. Spoilers ahead. This list is in no particular order.
Dexter, Lady Vengeance, and other scariest serial killers in Dexter: Resurrection
1) Dexter (Michael C. Hall)

The titular character is by far one of the scariest serial killers in Dexter: Resurrection because fans know exactly what he is capable of. His cold-blooded killing spree has been well-documented across four shows, and his motives are so plausible that it is impossible not to root for him while being scared senseless of his capabilities.
Dexter has been in the game since the '90s, and his kill count is over 150. However, his prey are other killers who have committed heinous acts. In a way, his actions can be explained as a twisted sense of justice. He is patient, stalking his victims and gathering evidence before closing in. Then he drugs them using "M99", before tying them naked to a table, and killing them with a knife to the heart.
While his murder victims were discovered in Bay Harbour, Miami, only a few came close to tying it back to him. His methods--hacking them into nine pieces and disposing of them--earned him the nickname "The Bay Harbour Butcher", but in Dexter: Resurrection, the serial killer has switched to incineration as his method of disposal. However, he continues to collect blood slides as trophies.
2) Mia Lappiere, aka Lady Vengeance (Krysten Ritter)

Mia's story closely mirrors Dexter's, so even though fans haven't seen much of her, they know how lethal she can be. Dexter also warms up to her immediately, which is a tell-tale sign of him recognizing her potential. Her vigilantism is an interesting modus operandi, and she is dubbed "Lady Vengeance" by the press in Dexter: Resurrection for exclusively murdering sexual predators.
Lappiere opens up to Dexter and the two share cackling chemistry in episode 4. However, her serial killer origin story is more saddening than scary. As a child, she had to get away from her mother's boyfriend, who was a pedophile and a r*pist. She finally snaps to protect her younger sister, Hazel, from him and kills him, thus starting her murderous spree.
The serial killer is reported to bludgeon her victims to death and even gouge their eyes out in her hunting ground, Boston, Massachusetts. Her bond with the titular character means fans will see more of her in Dexter: Resurrection.
3) Ronald "Red" Schmidt (Marc Menchaca)

Apart from Dexter, Red is the only serial killer to get ample screentime so far in Dexter: Resurrection. The titular character learns from his new friend, Blessing, of the "Dark Passenger", a serial killer who targets rideshare drivers. His operation was grotesque, as he attacked his drivers using a gigli saw and decapitated them. He then smeared their blood on their driving licenses to keep as a trophy.
Grief can cause people to do deeply disturbing things in the Dexter universe, and Red's story reiterates that. His father used to be a cab driver, but lost his job and took his own life after rideshares were introduced. Broken and angry about losing his father, he went after several rideshare drivers before Dexter killed him.
Red could've become scarier if not for his premature death on the show. He introduces Dexter to the network of serial killers, which means he could've been way more powerful than he let on.
4) Lowell, aka The Tattoo Collector (Neil Patrick Harris)

Knowing Lowell worked at a hospital as an anesthesiologist makes him one of the scariest serial killers on Dexter: Resurrection. His specialist skill, combined with the urge to kill, could mean anybody who crossed his path was a target. He used anesthesia to put his victims under before killing them and carving the tattoos off their skin as trophies.
However, he revealed that he chose his victims based on their unique tattoos, and not simply because they had one. So nobody knew who his next victim would be, making him volatile. He claimed that he took his victim's tattooed skin to calm down and release the pressure he felt to kill more. Without doing so, he might have gotten sloppier. In a way, the tattoos were his anchor.
Dexter killed and incinerated him in episode 4 of Dexter: Resurrection, knowing he could save Lowell's next victim. He took a blood slide as his trophy before stabbing him clean in the heart.
5) Gareth, aka the Gemini Killer (David Dastmalchian)

Fans have long learned not to trust the mysterious serial killers in crime dramas because they end up being the scariest of them all. Gareth the Gemini Killer is a great example of this. He is at Leon's dinner, and everyone calls him the stereotypical loner, but nobody knows more than that.
Is his name a play on the real-life Gemini Killer? Or does he have a different back story? It would be interesting if the showrunners dug deeper into his modus operandi.
Although the New York Ripper hasn't been introduced yet, the serial killer is being set up as a force to reckon with. Catch Dexter: Resurrection on Paramount+.