Clark Kent might get involved because he witnesses some injustice regarding Harry's custody. For instance, he could see Harry being mistreated by those who currently have custody or see some illegal activity in the custody process.
Perhaps in this fanfiction, Harry has some sort of special ability or connection that draws Clark Kent's attention. Clark, being the upstanding hero he is, decides to use his influence as Superman to make sure Harry is placed in a proper and loving custody situation. For example, he could convince a judge who is a big fan of Superman to look more closely at the case.
Well, Harry's magic could be used to enhance Clark's invulnerability. For example, Harry could cast a spell on Clark that makes his invulnerability even stronger. On the other hand, Clark's super - strength could be useful in a magical battle. He could physically move large magical structures or enemies.
Maybe Sirius gets help from some powerful wizards or witches who believe in his innocence. They might testify on his behalf in front of the wizarding authorities. Sirius also could show his strong emotional bond with Harry. He has always been there for Harry in spirit, and now he can be there physically to raise him, which convinces the authorities to give him custody.
One way they could be related in fanfiction is through a crossover of universes. Maybe a magical event in the Harry Potter world causes a rift that leads to the world of Clark Kent. And the two characters might have to team up to solve a problem that affects both their worlds.
They could interact as friends. Clark, with his super strength and other powers, could help Harry in physical battles, while Harry could use his magic to solve problems that Clark's powers can't handle, like dealing with curses or invisible enemies.
One idea could be a crossover where Harry Potter accidentally travels to the world of Clark Kent. He could be discovered by Clark, who is intrigued by this strange boy with magical powers. They might team up to fight a common enemy that is threatening both the wizarding world and Metropolis.
In most Outsiders fanfictions, Darry gets custody through showing his responsibility and commitment to taking care of his siblings.
An idea could be that Clark Kent, while on an investigative journalism assignment, stumbles upon the wizarding world. He meets Harry Potter, and they realize that their destinies are intertwined because a powerful dark magic is affecting both the Muggle and superhero worlds. They start to work together, with Clark using his super - speed to help Harry in his quests, and Harry using magic to protect Clark from certain magical threats.
One common theme is the clash of two different worlds. Harry comes from a magical world and Clark from a world of super - powers and modern technology. Another theme is friendship or mentorship, like Clark guiding Harry in the use of his powers in a different way or Harry introducing Clark to magic.
Sure, there are quite a few pieces of 'Harry Potter x Clark Kent fanfiction'. These fanfics often explore really interesting concepts. For example, they might imagine a scenario where Clark Kent, with his superpowers, enters the wizarding world of Harry Potter. Or perhaps Harry Potter finds himself in Metropolis. The crossovers can lead to some really unique storylines, like how Clark's powers would be perceived in the wizarding world or how Harry would handle the high - tech and superhero - filled environment of Clark's world. You can explore different fanfiction platforms to discover these gems.