It's late and I'm tired so my day 1 entry is small, a headcanon
Day 1 is Spring.
I think that Mytho/Siegfried, post canon, learns to control his flower powers better. And as he learns, he makes flowers for Rue regularly. She finds them lovely, she likes flowers, but she still harbors some guilt and worry and can't truly accept his daily offering wholeheartedly. She will enjoy them, but still feels she doesn't deserve them.
But then one day, someday, he takes her to a field in winter. And then he makes the *entire field bloom for her*.
She's impressed, and also floored. Why? What purpose does he have? Even as she's touched in her heart she can't grasp what's going on.
And he holds her and explains how she bloomed all on her own in the harshest of places, and how she's not alone anymore, and she's in a better place but only if she lets herself be. How he saw her beauty and strength alone and knows she would flourish if she could accept the love and support of those around her, of him. Of how she's been so strong for so long but there is beauty and joy and relief in reaching out and being part of a larger world that supports each other. How she is progressing on that and to not give up even during hard times, to ask him for help.
He explains that he would make the world bloom for her if he could, to just let her smile a little longer. How she deserves happiness and he wants to help her have it, always.
It's her turn to have spring.
And she breaks down crying and Mytho is a bit confused and worried, but she laughs a tiny bit at his concern and just hugs him. Which he knows what to do with; he holds her and they have an exquisitely touching moment in the field.