A possible plotline could be Loki having to prove his loyalty to the Avengers. After some initial distrust, they give him a chance to redeem himself. He has to go on a solo mission where he has to face an old enemy from Asgard who has now come to Earth. If he fails, not only will he lose the trust of the Avengers forever, but also put the world in great danger. During this mission, we see his character development as he struggles between his old self and the new self he wants to become.
Another plotline might involve Loki getting caught in a time - loop within an Avengers - related adventure. He keeps reliving the same day, and each time he has to interact with the Avengers in different ways to try and break the loop. This could lead to some really comical and also tense situations as he tries to figure out what's going on while the Avengers are getting increasingly suspicious of his behavior.
One plotline could be Loki initially resisting the Avengers' attempts to adopt him. He might be suspicious of their motives, thinking it's a trick. But over time, as they show genuine care, he starts to open up. For example, Thor could be a key factor in getting Loki to trust the Avengers, as he vouches for their good intentions.
One possible plotline could be that future Loki comes with a warning about a new threat that the Avengers initially don't believe. For example, he might tell them about a powerful being from another dimension that is slowly making its way to Earth. Another plotline could involve future Loki trying to redeem himself in the eyes of the Avengers by helping them prevent a disaster that he was partly responsible for in his own timeline. He could use his knowledge of magic and trickery to outwit the new enemy.
Often, there's a plotline where Loki has some inside knowledge about an enemy that the Avengers are facing. Maybe he has some past connection with the villain. So, he becomes a key source of information. There could also be a plot where Loki's presence in the Avengers causes some internal conflict within the team. Some members don't trust him, while others see his potential. This conflict and how it's resolved is a common plotline too. And sometimes, Loki might get kidnapped or held hostage by the enemy because of his new - found alliance with the Avengers, and the team has to rescue him.
One popular plotline could be Loki being the new student in high school where the Avengers are also students. Loki might initially try to cause trouble, like pranking the other students or trying to steal something important for a school event. Another plotline could involve a school competition where the Avengers and Loki are on opposing teams, and they have to learn to work together in the end. And there could also be a plot where Loki has a secret crush on one of the Avengers and tries to hide it while still being his mischievous self.
One interesting Loki and Avengers fanfiction could be where Loki is forced to team up with the Avengers against a greater threat. Maybe an ancient evil that even Loki realizes is too dangerous to face alone. He grudgingly works with them, and along the way, there are lots of humorous exchanges as the Avengers don't trust him at first.
A lot of fanfiction focuses on Loki's redemption arc within the context of the Avengers. For example, Loki could be injured and the Avengers take him in instead of imprisoning him. This leads to him slowly seeing the value in their cause and starting to change his ways. He might start using his powers for good, like helping Thor understand some new magical threats, which also helps to strengthen the bond between him and the Avengers.
There are quite a few potential plotlines. For example, imagine that a powerful magical artifact from the Harry Potter universe is stolen by Loki and he uses it to create chaos in both the Avengers' world and the wizarding world. At the same time, a character with the same unpredictable nature as Ledger's Joker emerges in the mix. The Avengers and Harry Potter characters would have to put aside their differences and use their unique abilities. The wizards could use their magic, the Avengers their superpowers, and they'd all have to deal with Loki's trickery and the chaos - causing character, leading to a complex and exciting adventure.
One interesting story could be about Thor and Loki having to team up against a new, powerful enemy that neither of them can face alone. This forces them to put aside their differences and use their combined powers and wits to save Asgard.
One interesting Young Avengers Loki fanfiction could be where Loki has to mentor one of the Young Avengers. He might use his trickster ways to teach them about the complexity of magic and the importance of out - thinking opponents. For example, he could help Wiccan control his powerful magic by showing him some of the more unorthodox methods he learned in Asgard.
A really cool scenario could be Loki using his shape - shifting abilities in a very creative way. He could transform into an enemy's most trusted ally and then manipulate the situation from within. By doing this, he can gather crucial information and use it to save the Avengers at the last minute. Maybe he discovers the location of a bomb or a weapon that is about to be used against the Avengers and is able to disable it just in time.