If Loki is in physical pain from an injury, the Avengers' resident doctor, Bruce Banner (when he's not the Hulk), could try to heal him. He might use his scientific knowledge combined with some Asgardian magic if Thor can provide it.
In case it's emotional pain, the other Avengers could show Loki acceptance and friendship. For example, Clint Barton could share his own experiences of redemption and how he was once seen as a villain but was given a second chance. This might help Loki overcome his pain and join the Avengers in fighting against the common threat.
It could be that Loki is in emotional pain due to being rejected by Asgard again. He's alone and suffering. The Avengers, especially those like Black Widow who understand the pain of being an outcast, reach out to him. They discover that an old enemy is planning to use Loki's vulnerable state to launch an attack on both Asgard and Earth. So they have to protect Loki and stop the enemy at the same time.
Loki could also provide the Avengers with valuable information about otherworldly threats. Since he has connections to different realms, he may know about an upcoming invasion. In return for his help, he could demand that the Avengers clear his name for some of his past misdeeds, leading to an interesting dynamic between them in the fanfiction.
If it's a magic - induced problem, then finding a counter - spell or a magical cure would be the way to go. He could go on a quest to find a powerful wizard or a magical artifact that can break the curse and restore his normal breathing.
In many Thor Loki Avengers fanfictions, Loki's character development often starts from a place of being the villain. He then gradually realizes the value of his relationships, especially with Thor. For example, in some stories, after seeing the loyalty of the Avengers to each other, he begins to question his own actions. He might start to show remorse for his past deeds like the attack on New York.
Kid Loki's character can be developed by showing his growth from a mischievous trickster to a more responsible hero. He could start by causing small pranks among the Avengers, but as he witnesses the real threats they face, he begins to use his skills for good. For example, his shape - shifting ability could be used not just for fun but to gather intelligence on enemies. Another way is to explore his past and how it affects his present actions. If he has a traumatic experience in Asgard, it could shape his relationships with the Avengers, like being overly cautious or overly aggressive in certain situations.
In fanfiction, Loki's survival can be justified through his magic. He is a master of illusions and trickery. So, he could have used a very advanced illusion to make it seem like he was killed when in fact he wasn't. He could have been biding his time, waiting for the right moment to re - enter the fray and help the Avengers against Thanos.
They show him kindness and try to understand his motives. They offer support and help him find a better path.
Communication is key. Peter could sit down with each of the Avengers and have an honest conversation about what went wrong and how he wants to make it up to them. He could explain his intentions behind his actions that they misinterpreted, like if he was trying to help but ended up causing chaos.
Well, Thor might be a bit shocked at first. He'd probably be amused by some of the wilder interpretations of his brother in the fanfiction. Captain America, on the other hand, would likely be confused by the whole concept as it's so different from the traditional stories he's used to. Iron Man would probably make sarcastic comments about how creative the fans are in coming up with these stories.
In some fanfictions, Loki might use his magic to outwit the enemies that the Avengers are facing. For example, he could create illusions to deceive the villains and lead them into a trap.