She may face some challenges in adjusting to her new form. Firstly, she'll have to get used to her new size and strength. She might accidentally break things or knock over her friends. Also, she'll need to figure out how to communicate effectively. Dragons might have a different way of expressing themselves, and Twilight will have to learn that while still being able to convey her thoughts to her pony friends.
Her curiosity might become even more intense. As a dragon, she has new abilities and a new form to explore, so she'll be eager to figure out all the ins and outs. For example, she'll be curious about how her dragon body works mechanically and magically.
One possible fanfiction could involve Twilight Sparkle's dragon transformation being a result of a powerful magic spell gone wrong. She might struggle to control her new dragon form and powers at first. For example, she could accidentally set things on fire when she tries to use her magic in her dragon state. As the story progresses, she learns to master her new form through the help of her friends.
One interesting story could be about Twilight Sparkle discovering a hidden dragon lair and having to use her magic to communicate with the dragons there. It might involve her learning about dragon culture and forging new friendships.
A likely candidate could be Discord. He is known for causing chaos and mischief. He might pretend to befriend Twilight Sparkle only to betray her at a crucial moment. Another possibility is Trixie. Trixie has been jealous of Twilight in the past and could betray her out of envy.
Flash Sentry could be a likely groom. He has shown an interest in Twilight in the past and they have had some interactions that could lead to a romantic relationship. Another option could be a completely new character, perhaps a powerful wizard or a prince from a far - off land who Twilight meets during one of her adventures and falls in love with.
At first, her friends would likely be in denial. They've known Twilight as a kind and good - hearted pony, so they might think there's some external factor causing her strange behavior. For example, Pinkie Pie might try to cheer her up with parties, thinking that would snap her out of it.
One interesting plot could be that Twilight's dragon transformation is part of a test by a powerful magical being. In her dragon form, she has to complete a series of challenges in a dangerous dragon - inhabited land. The challenges could be related to controlling her new form, using her dragon - specific powers, and also learning about the history of dragons. This would not only test her physically but also her mental and emotional strength.
I'm not sure of specific writers off the top of my head, but you can start by looking at popular fanfiction platforms. Check the reviews and ratings of Twilight Sparkle dragon fanfiction. Writers with high ratings and positive reviews are likely to be good.
Fanfiction about Twilight Sparkle being banished can also be a vehicle for exploring different relationships. Maybe she meets characters she would never have interacted with in the show. Her banishment could bring out different sides of her personality. She might become more resourceful or develop a stronger sense of self - reliance as she tries to navigate her new situation.