Well, initially there would be shock. They might not believe it at first. Aqualad would probably try to keep the team together and focused, but inside he's hurting. Miss Martian could have a hard time controlling her emotions and might accidentally use her powers in a way that shows her distress. They would all start to question their own abilities and the safety of their missions. They might also become more determined to honor Wally's memory by being better heroes and making sure his sacrifice wasn't in vain. They would likely have a lot of internal conflict as they deal with their individual grief while still trying to function as a team.
The team is devastated. Artemis might go into a deep state of grief and blame herself for not being there to protect him. Robin could become more withdrawn and focused on finding out who or what caused Wally's death. Superboy might struggle with anger, feeling like he should have been stronger to prevent it.
Well, in certain fanfictions, his death could be a result of a villain's elaborate plan. The villain might have found a way to disrupt the speed force that powers Wally. They could have created a device that nullifies his powers temporarily, and then, while he was vulnerable, dealt a fatal blow. This would be a tragic turn of events, especially for his friends in Young Justice who rely on him.
The rest of the team would be a mix of shocked and excited. Superboy might be a bit skeptical at first, thinking it could be some kind of trick. But once he realizes it's really Wally, he'd be glad to have another teammate back. Aqualad would probably be more diplomatic, welcoming Wally back but also being cautious about how his return will affect the team.
The emotional impact would be far - reaching. For the Young Justice team, it would be like losing a part of their family. There would be a lot of guilt, not just from Artemis but from others who might think they could have helped. His death could also lead to a change in the team dynamics. They might become more cautious, or some members could become more reckless in their attempts to avenge him. It would be a very difficult time for everyone involved in the Young Justice universe in the fanfiction.
Wally's magic can add a new layer of complexity to the story. It can be used as a plot device to overcome seemingly impossible obstacles. For example, if the team is trapped in a time - loop, Wally's magic - related speed power could break the loop.
In some fanfictions, Wally is often portrayed as a bit of an outcast due to his immortality. He feels different from his friends and teammates. His personality might change too. He could become more reserved as he witnesses the passage of time around him. But at the same time, he still has that underlying heroism that makes him a great character.
Fanfiction often shows their romance as a slow - burn. It starts with the two of them being friends and partners. They have a lot of banter and teasing at first, which is a sign of their underlying attraction. For example, in many fanfics, Wally's quick - witted remarks to Artemis are his way of getting her attention. As the story goes on, they start to realize their deeper feelings. This is usually shown through moments of vulnerability, like when one of them gets injured and the other is extremely worried.
Some members of the team might be overjoyed. They could see it as a sign of new life and a positive change for Spitfire. Others might be more cautious, worried about how the pregnancy will impact their ability to fight crime. For example, Batman - if he's part of the team's leadership - might be concerned about their safety and the potential risks to the unborn child during missions.
They would be devastated. Some might go into a state of shock and denial at first. For instance, Robin might isolate himself to try and figure out if there was anything he could have done differently. Superboy could become extremely angry and start lashing out, blaming others or himself for not being able to protect Blue Beetle.
Superboy would be devastated. He has a special bond with Miss Martian, and her death would likely make him go into a rage. He might start lashing out at the enemy without thinking, blaming them for her death. Aqualad, as the leader, would feel a great sense of guilt. He would question his leadership and decisions that led to the situation. He might become more withdrawn and overly cautious in future missions.
Some members of Young Justice could be embarrassed. For instance, if there are romantic fanfictions about them that are a bit too cheesy or if their weaknesses are overly emphasized in a not - so - flattering way. But others might be really intrigued and want to explore more of what the fans think about them.