Warning: The following review contains spoilers for the episode.
Secrets are being revealed and lives are being saved as Episode 31 wastes no time diving into things. After so much build up, learning some truths is exciting, and they reveal a lot about the strange events that have been going on throughout the series. However, poor execution of these scenes and an awkwardly blunt reveal leave much to be desired.
It seems Ymir has more to do before she passes on. I did find it a little tedious that Historia had to try and convince Hange Zoe that Ymir was on their side. The proof was clear and there were countless witnesses to the event. Obviously this is meant to tie back in with Eren and how he was treated upon his reveal as a titan, but at this point in the series that doesn’t make much sense. Humanoid titans are no longer an unknown, and it seemed odd there would be any doubt about Ymir’s allegiance given everything she just did.