I think Superboy would be really interesting. In Young Justice, he's still finding his place and dealing with his Kryptonian powers. In the Injustice universe, he'd be faced with a very different version of Superman. He could be a bridge between the two worlds, trying to understand the darker side of power that the Injustice Superman has embraced while also holding onto his own ideals from Young Justice.
Artemis could also be a great focus. She has a complex backstory in Young Justice, and in the Injustice world, she could use her skills as an archer and her street - smart attitude to navigate the chaos. Maybe she'd be part of a resistance group in the Injustice world, using her stealth and combat abilities to take on the regime. And her relationships with the other Young Justice characters could add depth to the story as she tries to bring them into the fight against Injustice.
Definitely Batman. He's a central figure in both universes, but in different ways. In Young Justice, he's a mentor, while in Injustice, he's fighting against a corrupted Superman. In a fanfiction, seeing how he'd interact with the Young Justice team in the Injustice world would be fascinating. He could be guiding them, but also learning from their more idealistic views. And his detective skills would be crucial in uncovering the secrets behind the Injustice regime and finding a way to overthrow it.
One idea could be exploring how the Young Justice team would react to the dystopian world of Injustice. For example, they might try to find a way to restore justice and balance without using the extreme methods seen in the Injustice universe. Maybe they would focus on rehabilitating the villains instead of just punishing them.
Superboy would be interesting as well. He's constantly trying to figure out his place in the world, and in a homefront fanfiction, he could be exploring his humanity further. He might get involved in community service activities to understand normal people better, which could lead to some really cool character development.
It could be Robin. Since he has a connection to Batman like Red Hood, he might have a unique perspective. He could be the one trying to understand Red Hood's motives and trying to bridge the gap between Red Hood and the rest of Young Justice. Also, his own growth as a hero could be further developed through this encounter.
Miss Martian from Young Justice could be a great focus. Her powers of telepathy and shape - shifting make her a formidable opponent. Also, her experiences as a young hero trying to fit in and be accepted, especially when facing the more established Justice League, can lead to some really interesting character development and plot twists.
Some fanfictions focus on the relationships between characters in the Young Justice Injustice scenario. Such as how friendships are strained or strengthened when faced with the moral dilemmas that the Injustice concept brings to the Young Justice universe.
One aspect to consider in 'Young Justice Injustice Gods Among Us Fanfiction' could be the character development. Writers often take the existing Young Justice and Injustice characters and put them in new and unique situations. This can lead to some really interesting changes in how we perceive the characters. For example, a character who was previously seen as a hero might be forced to make morally ambiguous decisions in the fanfiction, adding depth to their personality.
Definitely Kid Flash. He has a connection to both Young Justice and The Flash. His relationship with The Flash could be explored further, like how he feels about being in the shadow of the more famous speedster while also being a key member of Young Justice. And his powers could be a great asset in the crossover, as he can keep up with The Flash in terms of speed to a certain extent.
Superboy is often a popular choice. His complex origin story, being a clone of Superman, gives a lot of room for exploration in fanfiction. Writers can delve into his identity issues and how he fits in with both the Young Justice team and in relation to the Justice League.
In a 'Young Justice vs Injustice League' fanfiction, the Young Justice team might use their teamwork and strategic skills to their advantage. They are younger and more agile, so they could potentially outmaneuver the Injustice League. For example, Robin's detective skills could be used to find weaknesses in the Injustice League's plans.
Definitely Superboy. His struggle with his identity could be interestingly explored in a gamer fanfiction context. He could be like a character in a game trying to unlock his true potential or find his 'true ending' so to speak.