Well, one possible plot could be that some powerful and evil Pokemon gain the ability to control human minds. They then use humans for their own purposes like building elaborate lairs or finding rare items. Maybe they force humans to fight against other Pokemon or even other enslaved humans in some sort of gladiator - like battles for their entertainment.
A plot might involve a particular Pokemon species that discovers an ancient power which allows them to enslave humans. They start by taking over a small village and gradually expand their control. The humans, being enslaved, have to follow the Pokemon's every command. Some humans might try to resist and form an underground rebellion, leading to a battle of wits and strength between the enslaved humans and the enslaving Pokemon.
One main character could be a human scientist who was once respected by the Pokemon for their knowledge but is now enslaved. They use their scientific skills to try and find a way to free themselves and others. On the Pokemon side, there could be a young and curious Pokemon that starts to question the practice of enslaving humans and eventually becomes an ally to the humans. And of course, there could be a powerful and mysterious Pokemon that is the mastermind behind the entire enslavement operation.
Well, it could be that some powerful and mischievous Pokémon develop a new ability to capture humans for some strange reasons. Maybe they want to learn more about human behavior or they are being controlled by an evil force that wants to use humans for some dark purposes.
One possible plot could be that the powerful pokemon legendaries, feeling that humans have overstepped their bounds in terms of exploiting the pokemon world. So they use their extraordinary powers to enslave humans, forcing them to work in areas like restoring damaged pokemon habitats. This would turn the normal relationship between humans and pokemon upside down.
It could also be that the 'enslaves' part is not literal in the sense of physical slavery. Perhaps Naruto has some kind of mental hold over Kushina. For example, he might have discovered a way to manipulate her memories or emotions, which gives him a form of control. This would be a more psychological form of 'enslavement' and could lead to a complex and twisted plot.
I'm not aware of any official 'naruto enslaves sakura fanfic' as it goes against the positive themes of the original Naruto series. Fanfics with such disturbing concepts are not in line with the spirit of the show which promotes friendship, growth, and respect among characters.
One possible plot could be that Harry discovers a powerful and dark magic spell that allows him to gain control over Bellatrix. He then uses this to his advantage to gather information about Voldemort's plans from her. Harry might struggle with the moral implications of enslaving someone, even a Death Eater like Bellatrix.
One idea could be exploring how the Pokemon's unique abilities are used to control humans. For example, a psychic - type Pokemon might use its mind - control powers. Another could be the power struggle between different Pokemon species over the enslaved humans.
One idea could be a world where humans and Pokemon have to compete in a series of challenges to share resources. Another could be a Pokemon rebellion against humans who have been mistreating them.
A plot might involve a crisis, such as a global environmental disaster. The countrys humans then have to pool their resources and knowledge. For example, the scientific minds from different countries collaborate to find solutions while the more labor - intensive efforts are divided among those with different skills from all over the world.
There could be a Ditto in the fanfic. Ditto can transform into other Pokémon or even humans. It could use this ability to infiltrate human society and figure out the best ways to catch them. And then there could be a group of human rebels who are trying to fight back against the Pokémon. They might have unique skills or knowledge that they use to outwit the Pokémon and rescue the captured humans.