Frieren: A New Elf Saves the Hero

If, after Himmel's death, Frieren discovered that his soul was imprisoned atop the Tower of God and used as an "eternal energy source," would she draw her sword again? This time, not for the world, but for him.

This isn't an adventure to save the world. It's the story of an elf who takes a thousand years to learn to say "I love you," then forgets it in a single second, all to snatch the hero back from the hands of God.