Bowser could be the main antagonist as usual. He might be jealous of Princess Peach's newfound popularity during the Showtime and decides to crash the event and kidnap her once again, leading to a rescue mission by Mario and his friends.
One idea could be that Princess Peach discovers a hidden power within herself during the Showtime event that allows her to communicate with the spirits of the Mushroom Kingdom's past rulers. She uses this newfound ability to learn ancient secrets and protect the kingdom from a new, unexpected threat.
They often interact as teacher and student. Luna, with her vast knowledge of the old magic, can teach Twilight things that are not found in modern magic books. For example, Luna might show Twilight how to communicate with the spirits of the night.
Twilight Sparkle and Princess Luna often have interesting interactions in fanfiction. Fanfic writers might explore their relationship in different ways. For example, some might focus on their friendship, showing how they support each other in ruling Equestria or in magical studies. Others could create adventures where they team up against a common foe. There are also stories that delve into their individual growth and how they influence each other's development.
One common theme is friendship. Since Twilight Sparkle values friendship highly in the original series, it often features in fanfiction as she uses it to solve problems or strengthen relationships. Another theme is magic. Twilight is a very magical character, so her magic and the exploration of new magic forms are often in these stories.
Well, a big theme is discovery. Twilight is always learning new things, whether it's about magic, history, or other cultures in these fanfics. Another is the theme of facing challenges. She has to deal with all sorts of problems, from powerful enemies to difficult moral dilemmas. Also, the theme of community is present as she is part of the pony community and has to interact with others to make things work.
One great fanfic could be 'Twilight's New Adventure'. In this fanfic, Twilight Sparkle embarks on a journey to discover a long - lost spell. It's full of mystery and showcases her intelligence as she deciphers ancient texts. The author does a wonderful job of staying true to Twilight's character, making it a really engaging read.
Princess Peach is diplomatic. She has to deal with various situations in the Mushroom Kingdom, from handling relations with neighboring kingdoms to dealing with the chaos that Bowser often brings. Her diplomatic skills help keep the peace and order in her realm, and she is always looking for ways to improve the lives of her people.
One possible plotline could be Twilight Sparkle dealing with the physical and emotional changes of pregnancy while still having to fulfill her princess duties in Ponyville. Another could be her friends helping her prepare for the arrival of the new foal, like Pinkie Pie throwing a baby - themed party.