One interesting plot could be Goku and Steven Universe teaming up to face a powerful new villain that combines the threats from their respective universes. For example, a gem - powered foe with Saiyan - like combat abilities.
There could be a plot where Baby Steven gets sick or injured in some way, and Pearl is extremely worried. She tries all her knowledge of Gem healing techniques, but since Steven is half - human, she has to figure out new ways to help him. She might seek advice from Garnet and Amethyst, and in the process, they all bond more closely as a family, with Pearl being especially protective of the baby Steven.
Obviously, Goku and Steven Universe themselves are very popular. They are the main characters that people are excited to see interact. Their different personalities, Goku's bold and straightforward nature and Steven's empathetic and kind - heartedness, make for great chemistry.
Perhaps past versions of the Crystal Gems meet their future selves. They could be shocked by how much they've changed, or they might learn valuable lessons from each other. The past Gems could see how their actions in the past led to the future they now inhabit, which could be a really interesting exploration of cause and effect.
In some 'Goku meets Goku fanfiction', they could team up against a super powerful enemy that neither could defeat alone. They would combine their signature moves like the Kamehameha for an ultimate attack.
One interesting Steven Universe fanfiction could be about the Gems exploring a new planet together. They might encounter strange new creatures and have to use their unique powers in unexpected ways. Another could focus on Steven's relationship with his human friends in a more in - depth way, like how they handle his Gem - related issues in their daily lives.
A third possible plot is that Goku and Chi - Chi meet in a parallel universe where their relationship is completely different. They could explore this new dynamic and learn from each other. Maybe in this universe, Chi - Chi is a powerful warrior herself, and they team up to fight a common enemy, which changes their relationship in their own universe when they return.
A 'Naruto meets Steven Universe' fanfiction could start with Naruto accidentally ending up in Steven's world. He'd be shocked by the colorful and strange environment. Steven would be the first to approach him, being the friendly and curious character he is. Naruto would quickly show his combat skills, which would amaze Steven. The Gems might be a bit more cautious at first. But as they learn about Naruto's good intentions, they start to work together. They could share their knowledge of different forms of magic or power. Naruto could learn about gem - based powers and how to use them in combination with his chakra. And they could all go on adventures to protect both their worlds from new threats.
In some versions, the female Goku could be part of a prophecy. The two Gokus meet, and at first, there is some confusion and misunderstanding. But as they get to know each other, they discover that they are key to fulfilling the prophecy. They combine their powers and defeat an ancient evil that was threatening both of their worlds.
Perhaps the reincarnated character has to face a situation where they are not fully accepted as Goku by his friends and family. They then have to prove themselves not just in terms of strength but also in terms of character, and in the process, they form new and deeper relationships with the Z - fighters.
There might be a fanfiction where Steven and Pearl go on an adventure to a new planet. In this story, they encounter strange new creatures and have to work together to overcome obstacles. It's a great way to explore their characters outside of the main storyline of the show.