The remaining leaders of Survey Corps have a daunting decision to make after defeating the Titans of Reiner, Zeke, and Bertolt. They have to decide who between Erwin and Armin should they save in “Attack on Titan” season 3 episode 18.
It can be recalled that both Erwin and Armin sacrificed their lives in episode 17 to defeat the Beast and Colossal Titans, respectively. Both their plans, albeit being suicide missions, successfully worked. Moving on to “Attack on Titan” season 3 episode 18, fans who have not read the manga are likely thinking they are now dead.
However, based on the events in the manga series, Eren is about to discover in “Attack on Titan” season 3 episode 18 that Armin is still alive despite being scorched alive by Bertolt's Titan. It is supposed to be an easy call to use their Titan serum to revive Armin until Floch arrives with a barely alive Erwin in tow.
Back in episode 17, viewers may recall that one of the recruits that charged on the Beast Titan actually survived the boulder bombardment. That recruit is named Floch, and he will arrive in “Attack on Titan” season 3 episode 18 with Erwin just before Levi gives Armin the serum.
Levi will confirm that Erwin is also still breathing. Eren and Mikasa will make the case on why Armin should be the recipient of the serum while Floch and Levi will do the same for Erwin in “Attack on Titan” season 3 episode 18. Levi argues that they must give the serum to the one who has more to contribute to their ultimate goal of saving humanity. On the other hand, Eren attempts to remind Levi of the many ways Armin has helped the Survey Corps.
In the end, it will boil down to the realization of Erwin and Armin’s individual dreams. In episode 17, the latter talked about his wish of seeing the ocean telling Eren that he cannot die without fulfilling it. On the other hand, Levi will recall Erwin had previously mentioned he somewhat gave up on his own dreams when he planned on the suicide mission to charge the Beast Titan. “Attack on Titan” season 3 episode 18 will air on Sunday, June 9.