WARNING: The following contains spoilers for Chapter #136 of Attack on Titan, "Devote Your Hearts," by Hajime Isayama, Dezi Sienty and Alex Ko Ransom, now available in English from Kodansha.
While the Attack on Titan anime is just entering its fourth and final season, its source material also continues to draw ever closer to a nailbiting conclusion. After the crushing death of Commander Hange Zoe, author Hajime Isayama has kept readers on their toes in regards to who the next major victim of Eren's genocidal rumbling will be. Chapter #135 made it seem likely that Hange's successor, Armin, could well be next; however, Chapter #136, "Devote Your Hearts" complicates this implication.
Not only is Armin still clinging to life, but the peculiar circumstances of his current status lead him to discover he's not the only one stuck in this precarious state: Zeke Jeager is with him.
Following their unsuccessful assault on Eren's Founding Titan form in the last chapter, Levi, Mikasa, Jean, Connie and Reiner were forced to make a speedy escape when Ymir/the Founding Titan called forth the powers of every Shifter inheritor in history to defend themselves. As Falco's flying Jaw Titan, along with Annie and Gabi, whisked them to safety, they could only look back in dismay at those they'd left behind: Pieck Finger's impaled Cart Titan body and Armin -- swallowed by a Beast Titan -- who was nowhere to be found.
In Chapter #136, when his comrades return to the Founding Titan to re-attempt their assassination of Eren and recover Armin, the new Commander is revealed to still be conscious; aware of what his friends are doing thanks to the telepathic link that all Eldians share. In a typically 'Armin' moment of depression, a spiritual manifestation of the young soldier's body berates his immobilized physical one for its "uselessness," which speaks to Armin's brains over brawn balance, and his frustrations therein. But, again, in a very Armin-esque way, he quickly rationalizes that still being aware of what's happening around him must mean he's not dead... yet.
This is when Zeke reenters the picture. The older Jeager brother hasn't been seen since Chapter #122, which is when Eren double-crossed him to take control of the Founding Titan and enact the Rumbling with Ymir. A more recent installment of the Attack on Titan manga showed Zeke's Beast Titan using his baseball skills to demolish an attempted aerial assault on Eren's wall Titan army, but it was soon uncovered that this was merely one of Ymir's puppets, not the real Zeke, throwing doubt on whether or not he was still alive. At the end of Chapter #136, Armin and Zeke -- both "eaten by Ymir" -- are brought together at the Path, the spiritual channel that links Ymir's Subjects to the Titans.
When Armin finds Zeke, he's shifting the sandy ground into a mound -- a small action that shouldn't go unnoticed. After all, this was the method that Ymir used to bring Zeke back from the dead after his last confrontation with Levi. It's not the only blink-and-you'll-miss-it reference to the Titan founder, either. When looking for the Titan that swallowed Armin (an okapi), Mikasa mistakes the beast for a pig more than once. As Isayama reminded us at the start of Chapter #135, the farm animals are a crucial element of Ymir's origin story: 2,000 years ago, she was punished by King Fritz for allowing some pigs to escape their pen -- setting in motion the sequence of events that led to her gaining the power of the Titans. On a symbolic level, pigs could also represent the enslavement Ymir has suffered from her entire life, and her entire afterlife until Eren freed her.
Clearly, Ymir's presence is everywhere even if she herself is nowhere to be found. While Mikasa and the others may be able to rescue Armin's physical body from her, it will be up to Armin -- and maybe Zeke -- to return in spirit from the Path that bound Ymir for so long.
