Although this episode's backstory is from Keith's point of view, the emotional core comes through the Yaeger family whose predicaments about who is fit to have a certain role applies to anything. I think the Yaeger family helped Keith a lot, that although he didn't realize it at the moment, he felt like he owed it to the Yaeger family by saving Eren from the thunder aftermath. In conclusion, this was one of the best flashback episodes because of all the emotional moments. Not that AOT has lacked them, cause mostly all of them are great and they give the characters a sense of depth that accounts for episode rewatchability.
Review of Bystander
