Well, one adventure could be a sort of treasure hunt within the quarantine area. They find an old map that leads to a stash of valuable items that Nick Fury had hidden away for emergencies. As they search, they run into booby - traps and puzzles that they need to solve together. Another adventure could be a time - travel experiment gone wrong. They were just messing around with some old Stark tech that was supposed to be a harmless time - viewing device, but it sends them into different time periods for short periods. They have to figure out how to get back to the present without changing history, all while being in quarantine.
They could have a mini - adventure within the quarantine zone. Maybe they discover a hidden room in the compound that has some sort of mystery element. For example, it could be a room filled with old technology from the early days of S.H.I.E.L.D. that they have to figure out how to work. Or they could have a cooking adventure, with Thor trying to make Asgardian food and everyone else either being horrified or pleasantly surprised by the results.
In fanfiction, the Avengers might have an adventure of the mind. Since they can't go out, they could explore virtual reality worlds together. They might enter a VR world that is a replica of a dangerous alien planet they once visited. There, they have to face the same challenges again, but this time it's a test of their mental and strategic abilities. Also, they could have an adventure of self - discovery. With the time on their hands, they could explore their own powers more deeply, like Wanda trying to fully understand the extent of her reality - warping abilities and sharing her findings with the others.
The Avengers in quarantine fanfiction would show some interesting relationship developments. Maybe Rhodey would visit from time to time, bringing some outside perspective. This could cause some friction as the Avengers are used to their own little world during quarantine. But it could also be a source of new ideas. Sam and Bucky might continue their banter but also become closer as they train together within the quarantine area. And Pepper could play an important role in keeping Tony in check and also in mediating any disputes that might arise between the Avengers members.
They could have an adventure in a parallel universe. In this universe, the rules of power and combat are different. Trunks and Pan would have to adapt quickly to survive and find their way back home. It would be a story full of new challenges and discoveries for both of them.
An adventure where they have to stop an evil force that is threatening both of their worlds. Naruto could bring his knowledge of sealing jutsu to prevent the evil from spreading, and Noire could use her leadership skills to gather allies.
Percy could have his water - controlling powers from his original story. In the Avengers fanfiction, this could be really useful against fire - based villains or in situations where they need to manipulate water for various reasons, like putting out fires in a big city during an attack or using water to create barriers against enemies.
They could have adventures where they explore new planets. Gohan's curiosity as a Saiyan and 18's fearless nature would make them great explorers. Maybe they'd discover a new form of energy on an uncharted planet that could help Gohan become even stronger or give 18 some new abilities.
They could have an adventure where they explore an old, abandoned mansion. Tsuna's pet might be the first to sense some hidden danger or a secret passage. The pet could lead Tsuna to discover a long - lost treasure or a clue to a mystery related to Tsuna's family history.
They could go on a journey to explore an ancient, forgotten part of the ninja world. Naruto's strength, Hinata's Byakugan skills, and Himawari's budding abilities would all come in handy. They might discover lost ninja techniques or artifacts that could change the Hidden Leaf Village for the better.
In an AU travel fanfiction, Izuku might have an adventure in a world ruled by a strict and oppressive regime. He would have to find a way to inspire the people there to rise up against the tyranny without using excessive force. He could also travel to a world where quirks are not the main form of power, but instead, it's a world of magic and sorcery. Here, he would need to learn new skills and adapt to a completely different power system. Additionally, he could end up in a world that is constantly in a state of flux, with landscapes and rules changing randomly, and he has to be constantly on his toes to survive and help those in need.
In a highschool fanfic, Deidara and Sakura could go on an adventure in the school's abandoned attic. They hear rumors of a hidden treasure or a mysterious artifact. Deidara is excited by the idea of finding something unique for his art, and Sakura is curious about the history behind it. As they explore, they face challenges like old booby traps and must rely on each other's strengths to get through.
They could go on a quest to find a lost Uchiha artifact. Naruto's strength and Mikoto's knowledge of the Uchiha heritage would be crucial in this adventure. Along the way, they might encounter various enemies and have to use their skills to overcome them.