While the character was previously seen in the first Defenders trailer, Elodie Yung, who plays Elektra, spoke with Entertainment Tonight in a Facebook stream at San Diego Comic-Con and elaborated on her character's return. Elektra was presumed dead, killed by Nobu Yoshioka in the second season of Daredevil, The Hand placing her corpse in a stone sarcophagus. When asked what fans could expect from Elektra in The Defenders, Yung summed it up with "bloody."
"Very bloody, very dark Elektra this season," Yung said.
The description of Elektra as dark and bloody fits the idea that the character may come back as a weapon of The Hand, having been revealed in the second season of Daredevil to be a "Black Sky," though it is still unclear exactly what the Black Sky is or how it or they connect with The Hand.
The Defenders will bring phase one of the Netflix Marvel universe to a close, and will likely set up the next big phase of the universe. In addition to the core four shows (Daredevil, Jessica Jones, Luke Cage, Iron Fist), the universe will also be adding a Punisher series to its schedule, though no release date has been announced.
The Defenders stars Charlie Cox (Daredevil/Matt Murdock), Krysten Ritter (Jessica Jones), Mike Colter (Luke Cage), Finn Jones (Iron Fist), Jessica Henwick (Colleen Wing), Rosario Dawson (Claire Temple), Sigourney Weaver (Alexandra), Elodie Yung (Elektra Natchios), Babs Olusanmokun (Sowande), Elden Henson (Foggy Nelson), Simone Missick (Misty Knight), Rachel Taylor (Trish Walker), Scott Glenn (Stick), Eka Darville (Malcolm Ducasse), Debbi Morgan (Delores), Carrie-Anne Moss (Jeri Hogarth), and Deborah Ann Woll (Karen Page).
Daredevil seasons 1 and 2, Jessica Jones season 1, Luke Cage season 1, and Iron Fistseason 1 are all available on Netflix now, while The Defenders is expected later in the year. The Punisher does not currently have a release date. Netflix has announced a second season of Jessica Jones and a third season of Daredevil, but no release dates have been announced for those either.