I don't know who Toby is specifically in this story without reading it. He could be a child, a little animal, or even an adult with a child - like sense of wonder during Christmas.
Since the title only gives us the name Toby in relation to a Christmas story, he could be a variety of things. He could be a kind - hearted person who spreads Christmas cheer around his town. Maybe he's a lonely soul who finds warmth and friendship during Christmas. He could also be a naughty character who has a change of heart during the holidays.
Toby could be anyone. Maybe it's a friend of the speaker, someone in a writing group, or just a fictional name used to make a general point about writing novels. Without more context, it's hard to say exactly who Toby is.
There could be a psychic character. This person might be able to sense things that Toby can't and help him understand the nature of the paranormal activities. Another character could be Toby's best friend who is skeptical at first but then gets drawn into the strange events.
She might survive by making use of her relationships. For instance, if she has some sort of connection with Loki (maybe from past encounters), she could call out to him telepathically (if there's some sort of magic involved). Loki, being the trickster he is, could then come and rescue her. Another way is that Darcy could use her knowledge of science to create a makeshift weapon or a device that would help her escape from Hydra's clutches. She could use the materials available in her cell to build something useful.
In a fanfiction, Darcy could be wearing special glasses that allow her to swim underwater for a long time, like some kind of high - tech Avengers gadget. She could be using this ability to spy on an underwater threat. The other Avengers might not be aware at first, and there could be some comical misunderstandings.
In literature, one of the most famous Darcys is Fitzwilliam Darcy from Jane Austen's 'Pride and Prejudice'. He is a complex character, initially seen as proud and haughty, but as the story progresses, we discover his true and noble nature. He falls in love with Elizabeth Bennet, and their relationship is full of misunderstandings and growth.
It could be an antagonist. Some villain who has a grudge against Toby or the group he is associated with. This villain might see Toby as an obstacle and deliberately target him to cause harm.
Darcy would likely be both fascinated and a bit intimidated. When it comes to someone like Hulk, she might be a bit scared at first but then get really interested in the science behind his transformation. And for Iron Man, she'd be amazed at his high - tech gadgets and might start asking a million questions about how they work.