Well, a cool plot for a 'master of the universe fanfic' might be that the Master of the Universe discovers a parallel universe where there is an evil version of himself. He has to figure out how this version came to be and stop him from invading his own universe. Another idea is that the Master of the Universe's powers start to fade for some mysterious reason. He then has to go on a quest to find the source of the problem and regain his full strength. Maybe he has to make a deal with some other powerful entities in the process, which could have unforeseen consequences.
One idea could be exploring the origin story of the 'Master of the Universe'. Maybe he was an ordinary person who stumbled upon a powerful artifact that granted him his powers. Another could be a story where the Master of the Universe has to face a new, unexpected enemy that challenges his powers in ways he's never experienced before. For example, an enemy that can nullify his powers temporarily. A third idea is a 'what if' scenario, like what if the Master of the Universe lost his memory and had to rediscover his powers and purpose while being hunted by his former enemies.
One idea could be an alternate universe where the ponies have different elemental powers. For example, instead of Twilight Sparkle being a unicorn with magic related to friendship, she could control time. This would change the entire dynamic of the stories and the relationships between the ponies.
One idea could be exploring how the characters' relationships change. For example, if Deku was a girl, how would her dynamic with Bakugo be different? Maybe Bakugo would be more protective in a different way. Another plot could focus on how the female versions of the male heroes deal with the challenges in the hero society, like discrimination that might be specific to female heroes. Also, a plot could revolve around a genderbend All Might and how she inspires the new generation of heroes.
One idea could be that in the parallel universe, the characters have different semblances. For example, Ruby could have a semblance that allows her to manipulate time instead of speed. Another idea is that the kingdoms have different relationships. Maybe Atlas and Vale are bitter enemies instead of allies. Also, the Grimm could be more intelligent and have the ability to form complex societies.
One idea could be a story where Steven, despite being blind, discovers a new power within himself that is related to his sense of touch. For example, he can sense the emotions of the Gems through their gemstones when he touches them. This would add a new dimension to his relationships with the other characters.
Well, an interesting plot could be that the alternate universe is a post - apocalyptic world. The Vongola Guardians are now survivors trying to rebuild society. Tsuna has to use his leadership skills not in the context of the Mafia but in leading a group of people to find resources and fight off other dangerous gangs. Another idea is that the alternate universe has a different timeline. Some characters are from the future and some from the past, and they all come together in a time - warped situation that creates a whole new set of conflicts and alliances.
Well, perhaps in the other universe, Harry finds that Voldemort is actually a hero. This would completely flip his understanding of good and evil. He could also meet alternate versions of his friends. For example, Ron could be a super - intelligent wizard instead of the more laid - back character he is in the original universe. And Hermione might be a powerful athlete rather than a bookworm. This would create a lot of interesting interactions and character development for Harry.
Well, in an MLP Dark Mirror Universe fanfic, a possible plot is that the Elements of Harmony are actually used for evil. The ponies who usually protect Equestria are now using the power of the elements to control and oppress others. There could also be a plot where the different pony races are at war with each other instead of living in harmony. Maybe the unicorns think they are superior and are trying to enslave the earth ponies and pegasi. And of course, the fanfic could explore how the friendships that were once strong in the normal Equestria are now broken in this dark mirror world.
In the 'evil rwby parallel universe fanfic', it could be that there is no Beacon Academy as we know it. Instead, there is a place where they train people to be evil enforcers. The relationships between the characters are also twisted. For example, Weiss might be in a power struggle with Ruby, constantly trying to undermine her to gain more control within their evil group. The world itself could be a darker version, with different kingdoms that are all in a state of constant war and strife.
One idea could be a gem oc who was created with a unique power that the other gems don't understand. For example, the power to communicate with non - sentient objects. This could lead to all sorts of adventures as the oc tries to figure out how to use this power and the other gems try to figure out if it's a threat or a valuable asset.
Here's a plot idea. A puppet master in the Naruto universe is cursed. Every time they create a new puppet, they lose a bit of their own life force. But they are determined to create the ultimate puppet to protect their loved ones. Another could be that a group of puppet masters from different clans come together to create a mega - puppet that requires all their skills combined. And a plot where a puppet master's puppets get infected by some sort of dark chakra, and they have to find a way to purify them without destroying the puppets that they've spent so much time and effort creating.