[SPOILERS for The Defenders ahead.]
A description for a new character in Daredevil season 3 hints at one of the comic book villains that Matt Murdock (Charlie Cox) will battle next. Production for the third season of Marvel and Netflix's Daredevil TV show is slated to begin this fall, with Cox returning alongside fellow series mainstays Deborah Ann Woll and Elden Henson as Karen Page and Foggy Nelson, respectively. Details beyond that, however, have yet to be revealed, though Daredevil season 2 and The Defenders showrunners Douglas Petrie and Marco Ramirez are expected to oversee Daredevil season 3 from behind the camera.
The final shot of The Defenders teased what's to come in Daredevil season 3, showing that Matt had survived the destruction of The Hand's New York headquarters at the end of the miniseries and was now being treated by a group of nuns. Moreover, that scene clearly draws visual inspiration from Frank Miller's "Born Again" Daredevil comic book story arc and has since prompted much speculation about how much that famous 1986 narrative will inform Daredevil season 3's overarching plotline. There are sure to be differences between the two, of course, and the aforementioned character breakdown may provide a clue about one of those very changes.
That Hashtag Show has revealed a breakdown for a new Daredevil season 3 character who is referred to as simply "Steve", but which THS speculates could, in fact, refer to the Marvel/Netflix version of the comic book villain Stanley Carter aka. Sin-Eater. For more on that, read the description of "Steve" below:
28-35, 5'9-6'1, Open ethnicity. An athletic but socially awkward FBI Agent, needs structure and rules to suppress the darkness inside himself. Athletic with medium build, responsible and resourceful, hair trigger temper. SERIES REGULAR
The Sin-Eater was introduced in Peter Parker, The Spectacular Spider-Man comic book issue #107, as a former S.H.I.E.L.D. agent who gains near super-human strength through experimental treatments and eventually became a vigilante, determined to punish (or kill, in certain cases) those in positions of power who had "sinned" and abused their authority. However, as is noted by THS, there is some question about whether or not Sony has their own plans for the character, as part of their developing Spider-Man antihero film universe.
There are certainly parallels between the Sin-Eater and Frank Castle aka. The Punisher (Jon Bernthal) in Daredevil season 2; meaning that while the former's appearance in Daredevil season 3 would be in keeping with the show's ongoing exploration of vigilantism and the line between the law and law-breakers, a Sin-Eater storyline could feel like a rehash of The Punisher's original story arc in the Marvel/Netflix corner of the Marvel Cinematic Universe. Then again, it sounds as though "Steve" will start out in a much-different place than Frank did, helping to distinguish their respective character journeys on Daredevil in the process.
Beyond that, it seems safe to assume that Sin-Eater (assuming he appears) won't be the sole antagonist in Daredevil season 3. Daredevil season 2 set the stage for Kingpin (Vincent D'Onfrio) to seek revenge against Daredevil in season 3 from prison, a la how the character sets out to dismantle Matt Murdock's life in the "Born Again" comic book storyline. There are also the longstanding rumors that Bullseye will make his MCU debut in Daredevil season 3 to consider - not to mention, the strong possibly that like Matt, Elektra Natchios (Elodie Yung) managed to cheat death yet again at the end of The Defenders. In other words: just like in "Born Again", Matt's life is probably about to become a whole lot more difficult.
The Punisher season 1 hits Netflix sometime in 2017. Premiere dates for the new seasons of Daredevil, Jessica Jones, Luke Cage and Iron Fist have yet to be announced.
Source: That Hashtag Show