'Agents of SHIELD': Who Dies in "Past Life"?

Tonight's episode of Agents of SHIELD featured a major character's death, but its one of the strangest deaths we've seen in the series so far.

SPOILERS for Marvel's Agents of SHIELD Season 5, Episode 10, "Past Life", follow.

On last week's episode of Agents of SHIELD, Kasius revealed that he had a seer informing him of things to come. This seer has allowed him to keep pace with SHIELD even though they've been given tips about the future from Robin Hinton's visions.

It turns out that seer is Elena "Yo-Yo" Rodriguez. The entire SHIELD team is stuck in a time loop where they go forward in time and see the world was destroyed, return home with knowledge of the future, and then end up destroying the world anyway. They're then forced to live out the remainder of their lives knowing that they failed and preparing for their own return to the future.

At some point in that dark future, Yo-Yo died. That wasn't the end for her though, because Kasius used Kree technology – the same technology used in TAHITI to bring Coulson back to life – to restore Yo-Yo to life.

Since then, Yo-Yo has been killed and restored multiple times over. Most recently, he restored her so that he could use her memories of what happened when she was sent to the future to stay ahead of SHIELD.

Things came to a head in tonight's episode. Kasius began to lose his grip on sanity after he discovered that Sinara was killed hunting SHIELD. After that, Kasius became determined to go down in a blaze of glory and take as much of humanity as he could with him.

After his Inhuman trainer, Ty, and his Kree guards failed to kill SHIELD, Kasius decided to make things personal. He went to collect his seer. He brought Yo-Yo to the arena where he used to pit Inhumans against each other. Eventually, Mack found them there. Kasius drank an alien substance that gave him berserker strength and then slit Future Yo-Yo's throat in front of Mack.

Mack and Kasius battled it out until Mack, with some help from Simmons, killed Kasius. Only afterward did he discover that the Yo-Yo who he traveled into the future with was still alive.

Yo-Yo wasn't the only death though. In addition to her future self and Kasius, Enoch and Deke also appear to have sacrificed themselves in order to make sure that SHIELD made it back to their own period of history.

Marvel's Agents of SHIELD will return to ABC on March 2nd.