What could happen if a human wakes up in an underground in fanfiction?

In this kind of fanfiction, Ash might wake up with new Pokemon - like abilities. For example, he could communicate with Pokemon in a more direct and profound way, like understanding their every thought and emotion just by looking at them. He might also find himself physically changed, perhaps having some physical features of a Pokemon, which could lead to all sorts of interesting adventures and interactions with his friends and other Pokemon trainers.

Well, one possibility is that Ash wakes up with all the powers of Mew. He could then use these powers to quickly become the best Pokémon trainer ever. He might be able to communicate telepathically with all Pokémon, understand their needs and desires instantly, and use his newfound psychic abilities to battle more effectively. For example, he could levitate his Pokémon during battles, giving them an unexpected advantage.

In the 'beerus wakes up early fanfic', maybe Beerus wakes up early and decides to go on a sudden hunt for the best food in the universe. He could startle the local inhabitants of the planets he visits as he demands the most delicious delicacies.

Well, perhaps they could start the day with a friendly chat over breakfast. Harry might share some of his wizarding world stories with Gabrielle, and she could be really fascinated by them.

One possibility could be a spell gone wrong. Maybe some dark magic or a misfired charm during a chaotic event in the wizarding world caused their minds to be altered and they unknowingly got married. Another idea is that it was part of a devious plot by someone who wanted to stir up trouble between Gryffindor and Slytherin. It could also be a result of a strange magical contract that they were unknowingly part of.

She may wake up in a situation where she is being hunted by vampires or other dark forces. It's possible that she meets a friendly vampire or witch who helps her understand the strange world she's now a part of. Or perhaps she stumbles upon a long - lost mystery that is crucial to the survival of the town and its inhabitants.

She might try to prevent all the tragedies that befell her family. For example, she could warn Ned Stark about the Lannisters' schemes, which might change the whole course of events in Westeros. Maybe she would also use her knowledge of future alliances and enmities to her advantage, forging new relationships and breaking old, harmful ones.

In this fanfic, Aang might use the extra time to practice his airbending. He could go to a secluded spot and work on new techniques or perfect the ones he already knows.

They might find a world full of advanced technology that they have a hard time understanding at first. For example, they could encounter flying cars or holographic communication devices.

Maybe the human was part of an experiment gone wrong. Scientists in the fanfiction could have been conducting research in the underground facility, and something happened that made the human lose consciousness and then wake up there, surrounded by the remnants of the experiment.