Well, without more context, it's hard to define the specific 'you gonna cry christmas story'. Maybe it's a story where a poor child experiences a magical Christmas and the kindness of strangers, which is so moving that it brings tears. It might show the true spirit of Christmas and how it can change lives.
The magic. HP is all about magic, and if it's good fiction, it'll have cool spells, amazing magical objects, and a great sense of wonder about the wizarding world.
Well, many 'tails x tails doll fanfiction' stories have a theme of growth. Tails may grow in his understanding of different beings, especially the rather strange Tails Doll. Tails Doll itself might also experience some sort of growth or change in these stories. Another common theme is the exploration of different worlds or dimensions. The authors often send Tails and Tails Doll on journeys to other places, which opens up a whole new set of possibilities for the plot. There's also the theme of overcoming differences, as they are two very different characters, and seeing how they bridge that gap can be very interesting in these fanfictions.
The chords for this song are not fixed. Some versions might use combinations like A, D, and E. It often depends on the musical style and the artist's choice.
One common theme could be friendship. Tails and Knuckles are both Sonic characters, and their relationship can be explored in terms of how they support each other as friends. Another theme might be adventure, as they often go on adventures in the Sonic universe. So, fanfictions might center around them going on a new adventure together.