Warning: spoilers ahead for the fifteenth episode of Agents of S.H.I.E.L.D. Season 5, called "Rise and Shine."
Agents of S.H.I.E.L.D. has gone in some seriously dark directions in Season 5, ranging from the destruction of the planet and subsequent enslavement of the human race by the Kree to poor Yo-Yo getting her arms sliced off by Ruby. The agents have been trying to find a way to save lives and prevent the end of the world, but it's already clear that they can't possibly succeed without sustaining some big losses, and the latest episode may have indicated that one (or even some) of those big losses will lead to major character death(s). "Rise and Shine" has us worried about most of the major characters, and not just the ones who were revealed as dead in the journey to the future in the first arc of the season.
On the one hand, S.H.I.E.L.D. has gone pretty hard on the idea that timelines can't be changed. No matter what the agents do since coming back from the future, they seem to be setting events in motion that will result in the destruction of Earth. Daisy has had her potentially world-destroying powers restored, Yo-Yo lost her arms, gravitonium is back in the mix, May and Daisy are determined to try and save Coulson... everything that future Yo-Yo warned of seems to be happening. If that's the case, we might want to start worrying about characters who didn't appear in any of the scenes set in the Lighthouse in the season's first arc. Mack and Coulson's fates in particular were troubling.
On the other hand, would Agents of S.H.I.E.L.D. really take us through a full season of the good guys trying to save the world, only for it to be permanently destroyed by the series finale? S.H.I.E.L.D. may get dark at times, but destroying the planet and ending billions of lives might be a bit too dark. It would be super depressing if, despite everything, the agents ultimately failed and the world ended. Throw in all the ways the future should have already been altered by the characters visiting the Lighthouse via time travel years before the world would be destroyed, and we have to assume that the future isn't 100% set in stone. The future having the freedom to change could mix things up for the rest of the season and give us the hope for a happy ending.
So, operating on the idea that the future isn't set in stone, read on for a breakdown of four characters who could be in danger of death after the events of "Rise and Shine." They probably won't all bite the dust, but evidence is mounting that they might not get happily-ever-afters.
Why She Might Die: Well, for one thing, poor Yo-Yo doesn't have her own arms anymore. Although Simmons was able to install some robot arms on Yo-Yo in "Rise and Shine," she could be mortally incapacitated if her arms malfunction. Fitz couldn't be trusted to help with the arms, Simmons is no genius engineer, and those arms were salvaged from the body of an enemy android. Also, Yo-Yo is the one character whose fate seems the most certain, and that could be very misleading. She was alive--if not exactly well--in the Lighthouse during the reign of the Kree, and she had a lengthy conversation with herself. Meeting her future self gave Yo-Yo a sense that she can't be killed no matter what she does in the present, and she already lost her arms. She may be reckless to the point of death if she continues to operate under the belief that the future can't be changed. I could see S.H.I.E.L.D. pulling a "Gotcha!" by killing off the one character who seemed destined to survive.
Why She Might Not: Hasn't Yo-Yo suffered enough? Killing off Yo-Yo after everything she's already gone through in Season 5 would be cruel and unusual. Besides, Yo-Yo's powers are a major asset to the agents, and the writers might not want her out of the picture. Let her get her future with Mack and those badass babies she wants!