In this fanfiction, Ash could be in a situation where the world of Pokémon is in danger from an enemy that is too powerful for normal Pokémon attacks. A mysterious figure gives him the ability to transform into Super Saiyan Blue. Ash then has to adapt to this new form quickly. He might struggle at first with the increased power and speed, but as he trains with it, he becomes a force to be reckoned with, protecting the Pokémon world in a whole new way.
One idea could be Ash getting transported to the Dragon Ball universe and somehow obtaining the power of Super Saiyan Blue. He could then use his Pokémon training skills combined with this new power to fight off powerful villains in the Dragon Ball world.
One idea could be a story where the Saiyan Blue form has an unexpected side effect. For example, it could start to drain the user's life force slowly but surely. Goku discovers this during a battle and has to find a way to either control it or reverse the effect while still fighting powerful foes.
Well, perhaps the Super Saiyan 4 semblance gives the character the ability to emit a powerful energy aura. This aura could have different effects, like being able to disrupt the Grimm's dark energy or even being used as a shield against attacks. In a fight, the character could expand the aura to push back groups of Grimm or focus it into a beam - like Goku's Kamehameha - to take out a strong enemy. It would be a very flashy and powerful semblance in the RWBY universe.
A great concept for a Super Saiyan crossover fanfiction would be to cross it with the Harry Potter world. Imagine a Super Saiyan wizard or witch. They could use magic spells while in their Super Saiyan form. Or perhaps a crossover with the God of War series, where the Super Saiyans fight alongside Kratos against the gods of that universe.
Well, an interesting plot could involve a fusion of the energy systems in both Naruto and Dragon Ball universes. Naruto, as Super Saiyan Blue Naruto, could be tasked with saving both universes from a threat that is causing the boundaries between the two to collapse. He would have to use his newfound powers, which combine chakra and ki, to stop the chaos and restore balance.
One idea could be Pan discovers a hidden power within herself that allows her to transform into a unique form related to Super Saiyan 4. Maybe she has to go on a quest to find the knowledge to fully control this power. Another plot could involve Pan traveling to a different dimension where Super Saiyan 4 is the norm and she has to prove herself among stronger Saiyans there.
She could go on a quest to find a lost Saiyan artifact that can only be accessed by a Super Saiyan. This would take her to different planets and introduce new characters.
It's interesting because it takes Ash out of his normal Pokémon - training routine. When he has Super Saiyan powers, he can do things that are completely different from what he usually does in the Pokémon world. For example, he might be able to fly and use ki blasts while still having his Pokémon by his side. Also, it allows for new and unique storylines that wouldn't exist in either the Pokémon or Dragon Ball series on their own. Writers can create all sorts of new adventures and challenges for Ash in this new, combined universe.
Maybe the reborn Saiyan has memories of their previous life and tries to use modern - day knowledge to change the fate of the Saiyans. For example, they could introduce new technologies or strategies for fighting that would give the Saiyans an edge. They might also try to prevent the destruction of Planet Vegeta by warning the Saiyans about Frieza's true intentions in a more convincing way than Vegeta did in the original story.
Well, you could do a time - travel based crossover fanfiction. Have a legendary super saiyan like Vegeta travel back in time to a different era in the Dragon Ball Z universe. He could meet his younger self and together they could face a new threat that was previously unknown. Or, a crossover with a video game world. Picture the legendary super saiyan Trunks entering the world of Final Fantasy and having to go on a quest there.
A unique plot idea could be that Naruto's friends start to gain similar Saiyan - like powers. For example, Sasuke could develop a form that is a combination of his Sharingan and Saiyan power, which creates an interesting dynamic as they train together to master these new powers. Or perhaps, Naruto's Super Saiyan 3 form is the key to unlocking a long - forgotten prophecy in the ninja world that involves saving the entire universe from a cataclysmic event. In this way, the story could expand beyond the normal boundaries of the Naruto series.