>>279809936
In case you are new I'll spoonfeed you:
>Akatsuki no Requiem
This was the credit song for season 3, a special video of the complete version was published long ago.
https://www.youtube.com/watch?v=OrQ0zZArUV8
In the beginning no one really thought anything of it until the one who created the visual said that it was connected to the ending.
From then on theory started and pic related was the interpretion many reached, which would align with the original final page teased a year and half before the ending was published.