How can the characters from 'Ben 10' and 'JLU' interact in a fanfiction?

In fanfiction, they might interact due to a misunderstanding at first. Maybe the Justice League sees Ben using his alien powers and thinks he's a threat. But then they learn that there are other forces at work that are endangering both their worlds. So they start to communicate and plan together. Ben can show the League his knowledge of different alien races and technologies, while the League can share their experience in dealing with big - scale threats on Earth.

The characters can interact through shared adventures. For instance, Ben and the Equestria Girls could go on a quest to find a magical item that has been lost. Ben's abilities with his alien forms can help in combat or traversing difficult terrains, while the girls' magic and knowledge of their world can be useful in solving puzzles related to the item.

Often, Batman is the brooding, strategic one while Wonder Woman is the powerful and morally upright hero. In JLU fanfiction, they might interact with Batman respecting Wonder Woman's strength and her connection to the gods. For example, he might ask for her help when dealing with a threat that has a supernatural origin. And Wonder Woman would respect Batman's intelligence and his ability to plan ahead.

The characters could interact through a portal that connects their two universes. For instance, Ben could be exploring different dimensions and stumble upon Remnant. Then he meets the RWBY team, and they start to exchange knowledge about their respective worlds.

The Autobots could see Ben as an interesting new ally. They might be initially cautious, but as they see him use his Omnitrix to transform and fight, they gain respect for his abilities. Ben, on the other hand, would be in awe of the Transformers' size and power. He could learn from them about advanced technology and use that knowledge to upgrade his Omnitrix. The Decepticons would likely see Ben as a threat or a tool to be used. They might try to capture him or the Omnitrix. Ben's alien forms could have different interactions with the Transformers. For example, XLR8 could be used to quickly scout out Decepticon bases, while Diamondhead could provide a strong defense against their attacks.

Some of Ben's more heroic aliens, like Upchuck, could have really funny interactions. Upchuck might accidentally eat some of the devil fruits or other magical items in the DxD world, causing all sorts of wacky effects. And the angels in DxD might be initially suspicious of Ben, thinking he's some kind of new unknown entity. But as they see him fight against common enemies, they could start to respect him. Ben, on the other hand, would find the whole concept of the different supernatural races in DxD fascinating and might want to learn more about their powers.

Perhaps Ben teams up with the JLU to fight a common enemy that is immune to the Justice League's normal attacks but can be affected by some of Ben's alien forms. They could start off not trusting each other, but as the story progresses, they learn to work together and combine their strengths. Ben could use his alien forms like Four Arms to provide brute strength in battles, while the JLU members use their strategic skills.

Ben might initially be very cautious around the Xenomorphs. He's used to his own set of aliens, but these are something entirely different. He could try to communicate with them using his alien forms' unique abilities, but it might not work as the Xenomorphs are more about instinct. The Xenomorphs, on the other hand, would probably see Ben as a threat or a potential host.

Ben would likely be the wild card. He'd be excited to show off his alien forms to the Young Justice characters. Aqualad might be a bit skeptical at first, but Robin could be intrigued by Ben's tech. Superboy might see Ben as a rival in terms of power.

Well, Ben could use his alien forms to help out the characters in High School DxD in battles. For example, if there's a fight against a powerful devil, Ben could transform into Four Arms and use his super strength. The characters in DxD would be amazed by his abilities.