Well, it could be really interesting. They might be amused by some of the creative interpretations in the fanfiction. Some might find it strange to see their own characters in different scenarios that the fans have come up with.
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.
I'm not sure which character you're referring to. Master Kai has a high chance of appearing in different novels and works because of this name. I will try my best to answer your questions if you can provide more context.
One great 'Young Justice Dimension: Justice League' fanfiction is 'The New Recruits'. It focuses on how new members are integrated into the team. The story has great character development and exciting action scenes.
Green Lantern might also be involved in team - building aspects in the fanfiction. His leadership skills from the Corps could be applied to help the Young Justice group become more cohesive.
Their relationship also has the potential to be a mentorship of sorts. Superboy, having been part of the hero world longer, can offer advice to Static on dealing with the media and public perception. Static can show Superboy how to better connect with the civilian population, as he has more experience on the streets.
Terra's powers in Young Justice fanfiction are usually her geokinetic abilities. She can manipulate earth and rocks. This makes her very useful in combat situations, like creating barriers or launching boulders at enemies.
In many Young Justice fanfictions, Blue Beetle is a symbol of hope and new - age heroism. His connection to the scarab, which is an otherworldly power source, gives him an edge. He can be used to bridge the gap between different groups of heroes, whether they are from Earth or have extraterrestrial origins. His character also has room for growth, as he discovers more about his powers and his place in the Young Justice world.
Susano Naruto in a Young Justice fanfic could be a threat. Imagine if his powers were misused or if he was brainwashed. His Susano form is extremely powerful and could cause a great deal of destruction in the Young Justice setting. The heroes would have to figure out how to stop him without killing him, adding an interesting moral dilemma.
One possible fanfiction could be where Nightwing gets his scars during a particularly brutal fight against a new, powerful villain in Young Justice. The story could focus on how he deals with the physical pain as well as the mental struggle of having visible scars that might make him seem more vulnerable to his enemies.