One adventure could be that they are on a quest to retrieve a lost magical artifact. Along the way, they encounter dark wizards who are also after the artifact. Harry and Lupin would have to use their wits and magic skills to outwit the enemies. Another possibility is that they journey into the Forbidden Forest together to solve a mystery that is affecting Hogwarts. They meet all sorts of strange and dangerous creatures and have to rely on each other to survive.
They could go on a mission to find a rare magical creature that is important for some reason. Maybe it has a power that can help defeat the dark forces. Or they might travel to a hidden magical place that Lupin once knew about from his own adventures as a young wizard. There, they face various challenges and have to use their combined knowledge of magic to get out safely.
In the fanfiction, Harry and Lupin might embark on an adventure to explore an ancient wizarding ruin. The ruin is filled with traps and puzzles that require both of their skills to solve. Lupin's experience and Harry's natural courage would be put to the test. They could also find themselves in a situation where they need to rescue a group of young wizards who have been captured by a dark wizard. Harry and Lupin would then plan a daring rescue operation, using their knowledge of magic and the layout of the enemy's lair.
In many such fanfictions, Harry might start off with a basic admiration for Lupin as his teacher. But as the story progresses, he could come to see Lupin as a true father figure. Maybe Lupin shows him kindness and understanding that Harry lacks from other adults in his life. This could make Harry's view of Lupin deepen from simple respect to a more profound emotional connection.
At first, it would become very strained. Harry might avoid Lupin at all costs. He would no longer trust Lupin and would be suspicious of his every move.
It could lead to a whole new dynamic in the wizarding world. Maybe they'd have more adventures together and play a greater role in protecting it.
I'm not entirely sure as I haven't read that specific fanfiction. It could be about Harry Potter having a new identity as Remmy Lupin for various reasons. Maybe it's a story exploring a different path for Harry within the wizarding world, or it could be a what - if scenario where he takes on Lupin's name for some kind of mission or adventure.
One possible reason could be his self - loathing due to his werewolf condition. He might think he's not good enough for Tonks and that she'd be better off without him, fearing that his lycanthropy could bring danger or a difficult life to her.
Lupin might use his own experience as a werewolf to relate to Harry. He could teach Harry how to control his thirst for blood, much like he controls his lycanthropy. For example, by using potions or certain meditation techniques.
They are popular because Harry has a connection to Teddy through his father, Remus Lupin. Harry can act as a father figure to Teddy, and this relationship has a lot of potential for emotional depth. It's a way to explore the idea of family and mentorship in the wizarding world.
Definitely Sirius Black. Since he was one of Lupin's best friends and also had a strong connection with Harry. His presence can add a lot of drama and backstory to the fanfiction.
One great fem Harry Potter and Remus Lupin fanfiction is 'A Different Path'. It explores an alternate universe where Harry is female and her relationship with Remus develops in a very interesting way. It delves deep into their characters and how they interact in a world full of magic and mystery.
One interesting fanfiction idea could be that Snape discovers a hidden Horcrux that Lupin unknowingly has in his possession. Harry Potter then has to figure out how to destroy it without harming Lupin. This would add a whole new layer of drama and mystery to the existing lore of the Harry Potter world.