I'm so sorry I know I've asked a lot about this topic but I want to relieve myself and my curiosity. You told me before that Erwin no longer loves Mary and that she was a person from the past, so why is it that whenever Erwin sees Nile he asks about her in the game Attack "Wings of Freedom" Erwin asks about her and says "How is Mary? Before she married you she was the cutest girl in the bar", and Nile replies that she is fine and that he is crazy for choosing the giants over her. And in the drama CD of Erwin monologue "I chose the path of fighting the titan over the girl I loved" Why do I see her name repeated a lot despite her unimportance and only a childhood crush . I hate it when they make her the center of Erwin's life or his only love that he will not love after her. What do you think of my words🥺?
Sorry it’s taken me so long to answer your ask, I’m a bit slow with everything at the moment. I know that @momtaku has already answered your ask and I agree with all the points that she’s raised. One thing I would add is that every time Marie is brought up, the point being made is that Erwin chose to fight Titans rather than settle down and have a family. Although I think the significance of Marie is frequently overstated (see @fallenrazziel's Mary Dok Card), what is important is Erwin’s decision to give up the chance of having a “normal” life in order to join the Survey Corps and pursue his father’s dream. This is a pretty fundamental aspect of Erwin’s character, which is emphasised in most iterations of the story. “Not choosing Marie” is convenient shorthand for Erwin’s decision, which is always highlighted as being in contrast to Nile’s, who does choose wife, marriage and family. This in turn sets up the scenes in the Uprising Arc that @momtaku has already mentioned.
I think it’s also worth adding that we don’t really see Erwin pining for Marie. There’s never any suggestion that he regrets his decision or still holds a torch for her. Quite the contrary, it appears that Erwin was happy to help Nile court Marie (see the Smartpass story Erwin’s Letter) and he remains on good terms with the couple (The incident of the scout’s mysterious advertisement).
Of course there is one other appearance by Marie that hasn’t been mentioned in this discussion. I'll leave you to draw your own conclusions from this...