Darkseid could be a potential main antagonist. He might view Superboy as a weapon that he wants to control. If he realizes that Batman is trying to shape Superboy into a hero of Earth, he would surely try to stop it. He could send his minions to attack Batman and Superboy or try to corrupt Superboy's mind from afar with his Omega Beams.
Well, perhaps Batman sees Superboy as a lost and powerful youth in need of guidance. He could take Superboy under his wing to teach him how to control his powers better and use them for good. Maybe they start by training in the Batcave, with Batman showing Superboy his high - tech gadgets and combat techniques.
In this fanfiction scenario, Black Canary adopting Superboy could bring a lot of interesting dynamics. Black Canary could teach Superboy about self - control and discipline. She has her own unique fighting style and combat knowledge which she could pass on to him. Also, she could offer him a more stable and nurturing home environment compared to what he might have had before.
Lex Luthor would be a great antagonist. He could see Superboy as a threat to his plans in Metropolis and try to find ways to discredit him or even eliminate him. Since Lois is a journalist, she might start to investigate Lex's actions against Superboy, which would put her in danger as well.
It could be a character who is jealous of the relationship between Roy and Edward. Maybe someone who wanted to adopt Edward themselves or has a grudge against Roy for taking Edward in.
One great 'Batman and Superboy Fanfiction' is 'The Mentor and the Protégé'. It really delves into the relationship between Batman and Superboy. Batman's brooding nature contrasts well with Superboy's more exuberant personality in this fic.
Obviously, Batman and Jason are the main characters. Batman is the mentor and adoptive father figure, while Jason is the young boy who is being taken under Batman's care.
Wally is another key character. He has super - speed which makes him a very dynamic and exciting character. In this fanfiction, he is in a position to be mentored by Batman, which will likely lead to a lot of character growth as he learns from Batman's experience and discipline.
There are several challenges in this fanfiction concept. Firstly, Superboy may struggle with identity issues within the new family. Is he still a weapon or a son? Secondly, Black Canary has to deal with the fact that Superboy is not an ordinary child. His powers can be unpredictable and difficult to manage. Additionally, there could be external threats that target Superboy because of his unique nature, putting both of them in danger and straining their new - found family relationship.
Superboy would likely become more brooding. Batman's influence would make him more cautious and less impulsive with his powers.