Danny Phantom himself would probably be an ally to Thor. They both have superhuman powers and a connection to other realms. Danny's ghost powers, which are somewhat otherworldly, could be seen as similar to Thor's Asgardian powers. They could fight side by side against powerful enemies that threaten both their worlds. And Danny's friends, Jazz and Danny's parents (if they understood the situation), could also be supportive allies to the Avengers in different ways, like Jazz providing psychological support or Danny's parents offering their unique scientific insights.
I think Sam from Danny Phantom would get along well with Black Widow. They both have a no - nonsense attitude and are strong - willed. Sam could teach Black Widow about environmental protection, and Black Widow could train Sam in more hand - to - hand combat skills. Also, Tucker might be an ally to Iron Man. Tucker's love for technology and his skills in that area would make him a great partner for Tony Stark. They could collaborate on creating new gadgets that combine Danny's ghostly technology with Stark's high - tech creations.
I think Sans and Iron Man could be great allies. Sans is intelligent in his own way in Glitchtale, with his knowledge of timelines and shortcuts. Iron Man is a tech genius. They could combine their knowledge to create strategies against common enemies. Iron Man might be intrigued by Sans' magic - like abilities and try to find a scientific explanation for them. Sans, on the other hand, would be impressed by Iron Man's high - tech gadgets.
I think Klaus and Loki could be likely allies. They both have a sense of mischief and are often underestimated. They might team up to outwit their more 'righteous' counterparts. Klaus has his vampire powers and Loki has his Asgardian magic and trickery.
Inuyasha and Thor could potentially be allies. They both have a sense of honor and are very powerful warriors. Thor with his hammer and Inuyasha with his sword could fight side by side against powerful enemies. Also, Captain America and Inuyasha might get along. Captain America would respect Inuyasha's fighting skills and determination, and Inuyasha would see Captain America as a worthy leader.
Ezra and Spider - Man would be likely allies. Ezra's ability to connect with animals through the Force could be useful when combined with Spider - Man's agility in urban environments. They could both use their skills to gather information or carry out stealth missions.
I think Danny Phantom and Spider - Man would make an interesting pair. They are both young heroes with a sense of humor. Danny could teach Spider - Man about the Ghost Zone, and Spider - Man could show Danny some of his cool web - slinging moves. They could also bond over the fact that they have to keep their identities a secret while still trying to do good in their respective worlds.
Obviously, the main character would be Danny Phantom himself, but in two different forms or versions. One would be the original Danny Phantom from the canon source, and the other would be a version created by the fanfiction. There might also be his friends like Sam and Tucker who could play important roles in helping the two Dannys understand each other and deal with any issues that arise from their meeting.
I think Red Hood and Hawkeye could be likely allies. They both have a certain level of street - smartness. Hawkeye is used to working in the shadows and using his skills without relying too much on superpowers, just like Red Hood.
Sailor Mercury and Batman could be likely allies. Sailor Mercury is intelligent and tech - savvy, much like Batman. She could help him with any technological problems he might face in his fight against crime, while he could offer her his combat and detective expertise. For instance, if there was a villain using advanced technology to cause chaos in both their worlds, they could pool their knowledge to stop the bad guy.
I think Superman would be the most likely. Superman is known for his kind heart and open - mindedness. He would probably see Danny as a young hero in need of some guidance and friendship. He wouldn't be too quick to judge Danny based on his ghostly appearance or powers.
The Joker could be a great villain. Imagine him getting his hands on some ghostly technology or artifacts from Danny's world. He would use it in his own chaotic and unpredictable way, causing mayhem in Gotham and also attracting Danny's attention. Danny and Batman would have to work together to stop the Joker's mad schemes.