Nico might be cautious at first, trying to understand what kind of threat Voldemort poses. Voldemort would probably see Nico as an oddity and a potential obstacle to his plans, so he might attack without hesitation.
In a fanfiction, their interaction could be full of tension. Nico's powers of the Underworld could be a mystery to Voldemort, and Voldemort's dark magic would be something Nico has never encountered. They might start by sizing each other up, with Voldemort taunting Nico to see his reaction, and Nico remaining stoic and ready to fight if necessary.
They would probably start with a bit of caution. Nico is used to his own world of demigods and Dumbledore to his wizarding world. But once they start talking, Nico might be curious about Dumbledore's magic, and Dumbledore about Nico's powers.
Well, if Nico di Angelo meets Voldemort in a fanfiction, it depends on the writer's take. Nico could see Voldemort as just another evil entity to oppose. He might use his connection to the Underworld to his advantage. For example, he could summon some undead creatures to fight against Voldemort's Death Eaters. Voldemort, on the other hand, would probably view Nico as a strange and unexpected foe. He might try to use the Killing Curse on Nico, but Nico's ability to disappear into shadows could make it difficult for Voldemort to land a hit.
It could also be James. James is a natural leader and is always looking to include interesting people in his circle. When he sees Nico, he might sense that there's something special about him. He'd probably start by asking Nico about his abilities and before long, they'd be chatting like old friends. Plus, James has a big heart and would be accepting of Nico quite quickly.
Nico could be a valuable addition in terms of his unique powers. His ability to manipulate shadows and travel through them would give the Avengers an edge in stealth operations.
The group as a whole would be very worried about Nico's well - being. They would put aside any differences they might have had and work together. They'd also be worried about what the kidnapper might be doing to Nico. They might fear that he's being tortured or used for some evil plan. So they would be in a hurry to rescue him before any real harm comes to him.
Well, first of all, Nico di Angelo has his own set of powers and a complex backstory from his original world. If adopted by Batman, he would have to adapt to a completely different environment. Batman would probably be strict but also caring. He'd try to understand Nico's powers and how to use them for good in Gotham. Nico, on the other hand, might struggle with the new rules and the lack of the magic - filled world he came from. But over time, they could form a strong bond like a father - son relationship and face all kinds of challenges together, from the Joker's schemes to other mystical threats that might seep into Gotham.
Most likely, it would be Harry Potter and Nico di Angelo. Harry is the main character in his world and is always the one to step forward when something strange is going on. Nico, being the son of Hades, has a certain air of mystery around him. So, when he appears in the wizarding world, Harry would be the one to approach him out of curiosity and a sense of duty to protect Hogwarts from any potential threat.
The relationship could develop through mutual respect. They both have unique powers and a sense of justice. As they fight side by side, they would start to trust each other more and more, and their relationship could turn into a strong friendship.
Nico would fit in by bringing his unique powers. His ability to control the dead could be a huge asset in battles. For example, he could raise an army of skeletons to fight alongside the Avengers. His shadow - traveling would also be great for quick getaways or surprise attacks.
Nico's powers could also bring a new element of mystery to the Avengers. His abilities are not like the typical superpowers the Avengers are used to. This could lead to new training regimens and strategies. The Avengers would need to figure out how to incorporate his powers into their existing battle plans. And Nico himself would have to learn how to work within the group's dynamics, which could be a bit of a struggle at first given the differences in their power sources and fighting styles.