A really interesting plot could be that an evil force is trying to create a rift between the Plumbers and Attea's people. Ben and Attea have to work together to expose the truth and prevent a full - scale war. They have to navigate through political intrigue, false accusations, and their own personal differences to succeed.
Maybe in the fanfiction, Attea is in trouble on her home planet and Ben, being the hero he is, goes to help her. Along the way, they discover a long - lost secret about their two species that changes their relationship forever. This could involve some cool battles and new alien forms for Ben to use.
In some 'ben 10 and attea fanfiction', Grandpa Max can also be a significant character. His experience and wisdom as a Plumber can guide Ben in his interactions with Attea. And there could be other alien characters from Attea's species who either support or oppose her, which also adds to the complexity of the main characters' relationships.
One idea could be a crossover where the Miraculous heroes and Ben 10 team up to fight a common enemy. Maybe an alien villain that is immune to the powers of the Miraculous but Ben's alien forms can counter. Another could be a situation where Ladybug's Lucky Charm combines with one of Ben's alien gadgets to create a super - weapon. And a third could be a story where Ben gets akumatized and the Miraculous heroes have to figure out how to save him without using brute force as his alien forms are very powerful.
One idea could be that the characters from RWBY and Ben 10 universes team up to fight a common enemy that threatens both their worlds. For example, a powerful alien race in the Ben 10 world that has somehow found a way to access Remnant (the RWBY world) and is causing chaos.
One idea could be that Ben uses his Omnitrix to transform into a Pokemon - like form. For example, he could turn into a fire - type alien that has the abilities of a Charizard. Another plot could involve Ben and Ash Ketchum teaming up to stop a powerful villain who is trying to capture all the Pokemon and use the Omnitrix for evil purposes. Maybe there's a device that can fuse Pokemon with Ben's aliens, creating super - powerful hybrids.
Perhaps a story where an old enemy of Ben's targets Rook to get to Ben. Ben feels guilty and protective. They go on the run, hiding in different places across the galaxy. Along the way, they meet some interesting characters who help them. In the end, they face the enemy together, with Ben using his Omnitrix and Rook using his upgraded Proto - Tool to defeat the bad guy.
A fanfiction plot could be about a new threat that is specifically targeting the Omnitrix and the Power Rangers' power source. Ben and the Rangers have to figure out how the enemy is doing this and stop them. Along the way, they discover a hidden connection between the two power systems that was unknown before. There could be some character development for both Ben and the Rangers as they struggle to protect what they hold dear.
One idea could be that an alien vampire infiltrates Ben's team. It pretends to be a friendly alien at first but then starts to slowly drain the energy of the other aliens. Ben has to figure out a way to expose it without endangering his friends.
One plot idea could be that Gwen and Lemon have to team up to rescue Ben from an otherworldly threat. They start off not getting along well due to their different personalities, but as they face various challenges during the rescue mission, they learn to understand and respect each other. Another idea is a time - travel story where they go back in time and accidentally change something in Ben's past, and then have to figure out how to fix it before it causes major disruptions in the present. A third plot could be that a new villain targets Gwen and Lemon specifically because of their connection to Ben, and they have to use their combined powers and wits to defeat the villain.
Well, a plot might involve a device in the Pokemon world that can temporarily give trainers the ability to transform like Ben. But it has a side - effect of attracting some of Ben's most dangerous foes. So, the trainers and Ben must work together to fight off these threats while also dealing with the chaos that the newfound powers are causing in the Pokemon world. They could also learn from each other's fighting styles and techniques during the battles.
One idea could be that the Nemetrix starts malfunctioning and gives the alien predators it controls some of Ben's Omnitrix powers. This would create a whole new set of challenges for Ben as he has to deal with enemies that are a strange mix of the two technologies.