His death in Season 3, Episode 18, "Midnight Sun," was a hard blow to the Scouts, especially when it was discovered that Armin was chosen to live instead of him. But judging where things are going in the anime, perhaps it's for the better that Erwin is gone now.

Is Erwin Dead in Season 2?

Levi gives Armin the serum instead, allows him to eat Bertolt, and tells Erwin that there will be a delay in his promise to kill the Beast Titan, as Erwin dies peacefully. ... Levi explains that it was ultimately him that chose to save Armin.

What episode is Erwin's charge?

As Erwin's heroic charge buys Levi time to confront the Beast Titan, Armin comes up with a plan of his own that lays it all on the line.