He could start learning Dragontongue when he's on a quest. For example, if he's searching for a powerful dragon - related artifact, and the only way to get more information about it is to understand the language of the dragons. So he has to find someone or something to teach him Dragontongue in order to progress in his quest.
One challenge could be the sheer complexity of the Dragontongue language. It's not like any language Harry has learned before. The grammar and pronunciation might be extremely difficult for him, especially since it's a language created for a completely different fictional world.
I'm not entirely sure if 'Harry is ancient xover fanfic' is a statement or a really oddly - phrased question. If it's a statement, it could mean that in a particular fan - created fictional universe, a character named Harry is part of an 'ancient xover' which might be a crossover with some very old or classic fictional elements. But without more context, it's hard to be more specific.
It could be Hermione. Since she's Harry's close friend, she would likely play a significant role in a story where Harry is immortal. She might be the one trying to help Harry adjust to his new state or be involved in his adventures in some way.
It depends on your personal taste. If you like crossovers between different fictional universes and are a fan of both Harry Potter and Skyrim, it could be really interesting. The combination of magic from Harry's world and the lore of Skyrim can create some unique and exciting storylines.
In this fanfic, an interesting aspect could be how Harry deals with the passage of time. He might start to view historical events and future possibilities in a different light. His immortality could also attract the attention of powerful and ancient magical beings who either want to use his immortality for their own gain or fear the implications it has for the balance of power in the magical world. This could lead to a whole new set of adventures and challenges for Harry.
In fem Harry is ancient xover fanfic, a prevalent theme is the clash of cultures. Fem Harry comes from a modern - day wizarding world in the Harry Potter series, and when she enters the ancient world, there are bound to be cultural differences. This can lead to interesting situations, like misunderstandings that she has to overcome. Another common theme is the exploration of gender roles. In the ancient world, gender roles might be more rigid compared to her own world, and fem Harry has to navigate through these expectations. Also, the theme of destiny often plays a part, as she may find that she has a special role to play in the ancient world she's been thrust into.
The plot could involve Harry arriving in Skyrim and being mistaken for a powerful mage. He gets caught up in the political intrigue of the different factions in Skyrim. For instance, the Stormcloaks might try to recruit him because they think his magic can give them an advantage in the civil war. Meanwhile, he's also trying to find a way back to his own world.
A 'cartoon xover fanfic' is a type of fan - made fiction that combines elements from different cartoons. It's like taking characters from one cartoon and putting them into the story world of another cartoon. For example, you might see a fanfic that has characters from 'Tom and Jerry' interacting with those from 'Scooby - Doo'. Fans create these to explore new and interesting story ideas that the original cartoons might not have covered.
For a 'harry potter stargate xover fanfic', Daniel Jackson from Stargate would be an interesting main character choice. His thirst for knowledge and understanding of different cultures would make him eager to explore the magical world of Harry Potter. On the Harry Potter side, Ron Weasley could be a main character. His loyalty and his ability to adapt to new situations could play a big role. And of course, Samantha Carter from Stargate with her scientific expertise could be involved in trying to figure out the scientific basis behind magic in the Harry Potter world if there is any.