One good Stiles - Avenger crossover is 'Stiles in the Marvel Universe'. It has an interesting plot where Stiles uses his wits from the Teen Wolf world to interact with the Avengers. Another is 'Stiles and the Avengers: An Unexpected Alliance' which shows how Stiles' unique skills could be useful to the Avengers.
Another character he could interact with is Thor. Thor's otherworldly nature and his powerful abilities would be quite a contrast to Stiles. Maybe Stiles could help Thor understand some earthly concepts while Thor could teach Stiles about Asgardian culture and power.
One possible plot could be that Stiles is a huge Avengers fan in his own world, and through some magical or scientific mishap, he gets to meet his heroes. But it's not all fun and games. He has to prove himself worthy of being part of their team. He could also bring in some of his own world's technology or ideas that help the Avengers face a new and powerful threat.
These crossovers are appealing because it combines two very popular universes. The Avengers have a huge global following, and so does Teen Wolf. Stiles is a beloved character, and seeing him in the context of the Avengers is exciting. It's like a mash - up of different genres. You get the supernatural - mystery elements from Stiles' world and the superhero - save - the - day elements from the Avengers' world. The potential for character development is also great. Stiles can grow in a new environment, and the Avengers can be influenced by his different way of thinking.
One great 'Hermione and Avengers' fanfiction is 'Hermione in the MCU'. It has an interesting plot where Hermione is transported to the Marvel Cinematic Universe and interacts with the Avengers in a unique way. The author does a great job of blending the magic from Hermione's world with the superhero aspects of the Avengers.
A really engaging fanfiction is 'When Spiderman Met the Original Avengers'. It takes place in a different timeline where Spider - Man meets the first - generation Avengers earlier than in the regular storylines. The story explores how his presence changes the dynamics of the team from the very beginning and how they all learn from each other.
Well, in some Moon Knight fanfictions, Avengers might team up with Moon Knight to fight a common enemy. For example, they could be facing a powerful new villain that neither could defeat alone. This could lead to some really cool fight scenes and interesting character interactions, like Iron Man providing tech support while Moon Knight uses his unique combat skills.
One interesting Stiles fanfiction is 'Stiles' Time - Travel Trouble'. Here, Stiles gets thrown into different time periods and has to find his way back. It's a fun read as it shows Stiles in various historical settings and how he uses his modern - day knowledge to survive. There's also 'Stiles and the Forbidden Friendship' which explores an unlikely friendship Stiles forms with a character from the other side of the supernatural divide.
I'm not sure about a specific 'bella is a avenger fanfiction' off the top of my head. But you can try searching on fanfiction websites like Archive of Our Own. There are likely many stories with that concept, and you can filter by popularity, ratings, etc. to find a good one.
One interesting crossover could be Stiles using his wits to outsmart Loki. Stiles is known for his intelligence in his own universe, and facing off against Loki's trickery would make for an exciting story. Maybe he could use his knowledge of the supernatural to help the Avengers deal with magical threats.
Fanfiction.net also has a decent amount of Avenger cast fanfiction. It has been around for a long time and has a large user base. You can find everything from short, sweet stories to long, multi - chapter epics on this platform. However, the search functionality might not be as refined as AO3 in some cases.