You never know or truly treasure what you have until it gone. If things has go as planned, Mei would have parted with Ely and everyone in a peaceful manner. While that's nice and all, it won't make a soul deep impression into Mei life, it won't make Mei engraved 13 Flamechasers into her very being. So for all the mess HoC has done, she has provide Mei a chance to finally recognize and acknowledge her love for the Realm, for 13 Flamechasers and especially Elysia. From when the Typewriter give out Elysia is dead message, that's when Mei start to worry and even losing hope about Ely still alive. That's why when she finally got a clue about the Keys, about how to revive Elysia she has gone after it with a passion and determination equal of when she left Kiana behind. In the end Mei has to acknowledge that she has once again fallen to another Hero, a lovely, loving and beloved one just like her Kiana, the most pure and noble soul Elysia
I don't have the time to play Honkai so I tend to go look around for people who posted the story and gameplay or read up to follow up with the events of the story, thank you so much for uploading these videos. This has helped tremendously in letting me experience part of the story.