A great plot could be centered around a prophecy that involves both Nico and Sirius. They are brought together by this prophecy which predicts that only by combining their powers can they save both the demigod and wizarding worlds. Along the way, they have to deal with people who don't trust their alliance, like some of the demigods who think wizards are too different and some wizards who are scared of Nico's connection to the underworld. But they persevere and fulfill the prophecy.
One possible plot could be that Nico di Angelo somehow gets transported to the wizarding world. He might initially be seen as a strange outsider with his unique powers from the demigod world. Maybe he teams up with Harry Potter to face a new kind of dark magic that combines the elements of the demigod and wizarding threats. For example, a villain who has found a way to use both the magic of the Underworld and the dark arts.
In a fanfiction where Nico di Angelo meets Dumbledore, there are numerous possibilities. Nico might be initially distrustful of Dumbledore, given his own experiences with authority figures. However, Dumbledore's calm and kind demeanor could gradually break down Nico's walls. Dumbledore could introduce Nico to the wonders of the wizarding world, such as spells and magical artifacts. Nico, in turn, could show Dumbledore some of his demigod abilities, like shadow - traveling. Their meeting could also lead to a cultural exchange of sorts, with Nico learning about Hogwarts and Dumbledore getting a peek into the life of a demigod.
In such a fanfiction, there could be an epic battle. Nico's powers from the Percy Jackson universe might clash with the Winchesters' hunting skills. Maybe they initially misunderstand each other, thinking the other is a threat. But then they could realize they are all fighting against some form of evil and team up. For example, Nico could use his ability to control the dead to help the Winchesters deal with a horde of zombies, while the Winchesters could teach Nico some of their combat tactics against demons.
One possibility is that Nico, with his powers over the dead, could really freak out Batman at first. Batman is used to dealing with normal criminals and the occasional super - villain with scientific powers. Nico's dark and otherworldly abilities would be something completely new to him. Maybe Nico would mistake Batman for some sort of undead creature at first because of his all - black costume and brooding nature.
In the fanfiction, Nico might find himself in some of the Marauders' pranks. Since the Marauders are known for their mischief, they could include Nico in one of their elaborate schemes against the Slytherins. Nico, being from a different background, might have a different perspective on these pranks and could either enhance them or try to stop them depending on his moral compass at that moment.
Well, Nico could use his powers to surprise the Avengers. Maybe his shadow - traveling ability would come in handy during a battle, like he could quickly transport himself and some Avengers to strategic locations.
Sirius is known for his rebellious and somewhat impulsive nature. Nico, on the other hand, is often moody and withdrawn. Their personalities could clash as Sirius might try to draw Nico out of his shell too quickly, which could annoy Nico. However, they could also complement each other. Sirius' boldness could inspire Nico to be more confident, and Nico's deep understanding of loyalty (from his experiences in the demigod world) could remind Sirius of the importance of true friendship.
Well, it could be about Nico Di Angelo using his underworld powers to help the Avengers in a battle against a powerful villain who has the ability to raise the dead. Maybe he teams up with Doctor Strange to close portals to the underworld that the villain is using to summon hordes of zombies.
Well, it depends on the plot of the fanfiction. If it's a crossover in a modern - day setting, Nico might be initially in awe of Diana's beauty and power. Diana, on the other hand, could see Nico as a young and powerful ally. They could exchange stories about their different worlds, Nico talking about Camp Half - Blood and Diana about Themyscira.
In a fanfiction scenario, Nico di Angelo and Captain America could team up. Nico could use his shadow - traveling abilities to get them out of tight spots. Captain America would bring his leadership and combat skills to the table. Their meeting might also lead to some interesting cultural exchanges, as Nico comes from a world of Greek mythology and Captain America from a more modern, American - military background.