What with the Kree's role in the greater Marvel Cinematic Universe ramping up, it sounds like that role could extend to the small screen once again.
Big things are happening in the Marvel Cinematic Universe as Phase Three heads toward next year's epic crossover event, Avengers: Infinity War. However, after the first installment of Infinity War comes the much-anticipated Captain Marvel movie, which will introduce a much bigger storyline to the MCU, in the form of the Kree-Skrull War.
Marvel fans have been buzzing about what it means to have the full Kree vs. Skrull history of Marvel Comics in the MCU, and now we may see some early lead-ins to that conflict being laid out, as Agents of S.H.I.E.L.D. looks like it will be bringing back the Kree for a Season Five storyline.
Check out how AoS star Chloe Bennet may have accidentally, revealed the Kree's return to the show:
As you can see in Bennet's Tumblr post above, there seems to be an actor donning Kree makeup for a scene in the upcoming season. Agents of SHIELD has been the main avenue of exploring the Kree alien race in the MCU, as samples of Kree DNA were responsible for helping resurrect Phil Coulson, and eventually led to the revelation of the descendants of Kree experimentation, the Inhumans, living on Earth.
With Captain Marvel about to open up the MCU cosmic side to the epic history of the Kree and Skrull empires' war with one another, it makes sense that AoS would bring the Kree back into focus, as they are also the main players in the origin story of how Air Force pilot Carol Danvers (Brie Larson) will become the hero Captain Marvel.
In Marvel Comics, The Kree-Skrull war is a story arc from the early 1970s, in which The Avengers get embroiled with Kree hero Mar-Vell, who is an agent of the Kree fighting in their war against the shape-shifting Skrulls. Marv-Vell winds up being a central figure in the ongoing war between the Kree and Skrull empires, due to his knowledge of the "Omni-Wave Projector," a weapon of deadly power.
The war ends when Mar-Vell is taken to the heart of the Skrull Empire to build the weapon, and various Marvel heroes (like the Avengers) show up to save the day. In the end, with help from the Kree Supreme Intelligence, Marvel sidekick Rick Jones has the all-powerful "Destiny Force" released in him, and uses that power to end the war.
Presumably, Captain Marvel will tell the story of how Carol Danvers comes into contact with the Kree (maybe through their operative on Earth, Mar-Vell?) and gains her cosmic power. That power will presumably make her a pivotal player in the Kree-Skrull War, and a key factor in changing its tide.
The actions wrought by Captain Marvel in the Kree-Skrull War may indeed set up the next great threat that the Marvel Cinematic Universe heroes have to face.