In some 'Harry has the Omnitrix' fanfictions, there could be a plot where the Omnitrix is actually a magical artifact from another dimension that was sent to Harry for a specific purpose. He then has to figure out what that purpose is. Along the way, he might face challenges like other wizards wanting to take the Omnitrix from him because they fear its power. Harry would have to use his wits and the different alien forms at his disposal to protect himself and the Omnitrix.
One possible interesting plot could be Harry using the Omnitrix to transform into various alien forms to battle dark wizards. For example, he might turn into a strong and durable alien to withstand powerful spells. Another plot could involve Harry trying to keep the Omnitrix a secret from his Hogwarts friends while still using it to his advantage in dangerous situations.
There could be original characters created specifically for the fanfiction. For example, a wizard who has some knowledge about the origin of the Omnitrix and tries to guide Harry. This character could be an old hermit - like wizard who has been studying interdimensional objects for years. Also, there might be a villain who is after the Omnitrix, someone who wants to use its power for evil purposes and constantly hunts Harry down.
In some Omnitrix fanfiction, there are crossovers with other universes. For instance, a story where the Omnitrix wielder ends up in the Star Wars universe. They have to use their alien forms to survive in this new and very different environment, facing off against Sith Lords and using their powers in creative ways to interact with the Force.
Well, perhaps the Omnitrix gets mixed up with the magic in Hogwarts. It starts malfunctioning and instead of the usual alien forms, it gives Harry forms of ancient wizards. He has to figure out how to control these new forms while also dealing with the mystery of why the Omnitrix is acting this way. And he might learn new spells and magic from these wizard forms.
Well, one interesting plot could be how Harry manages to balance his new role as a father of triplets while still dealing with the wizarding world's threats. Maybe the triplets inherit some unique magical abilities that draw both good and bad attention.
Sure. One idea could be that Harry discovers the Omnitrix during a trip to the Forbidden Forest. He initially has no idea what it is but as he experiments with it, he realizes its potential. He then uses it to secretly train himself, away from the prying eyes of his teachers and classmates. Another idea is that the Omnitrix is sent to him by an unknown wizard from a different dimension who thought Harry could use it to fight Voldemort more effectively.
What if the Omnitrix was actually a gift from a legendary Pokemon? In this fanfiction, Ash is chosen to receive it because of his pure heart and strong will. However, using it comes with a price. Every time he transforms, it drains his energy, and he has to find a way to replenish it. This could involve seeking out special items or places in the Pokemon world. His friends would have to help him manage this new challenge.
One interesting concept could be how the Omnitrix interacts with the unique chakra system in Naruto. Maybe it could transform the user into Naruto characters with added alien abilities from the Omnitrix. For example, turning into Naruto with the powers of Heatblast, allowing for a super - charged Rasengan with fire - based attacks.
Another could be an OC with the Omnitrix getting stuck in a parallel universe where the rules of the Omnitrix are different. For example, instead of being able to transform into known aliens, the OC has to figure out how to use new and strange alien forms that are native to that universe. This could lead to all sorts of adventures as the OC tries to find a way back home.
One idea could be a story where the Omnitrix is fused with a Pokeball, allowing the protagonist to transform into a Pokemon and use its powers while also being able to capture other Pokemon in a unique way. Another could be a cross - over where characters from Ben 10 (where the Omnitrix is from) end up in the Pokemon world and have to use the Omnitrix to survive and understand the new environment. A third idea is a story where a Pokemon trainer discovers an ancient Omnitrix - like device that gives them the ability to transform into rare and powerful Pokemon forms that no one has ever seen before.
One interesting storyline could be about Ben exploring new alien forms that were previously unknown in the official series. Maybe he discovers a form that has unique powers that he has to learn to control quickly to face a new and powerful enemy.