Definitely Vegeta. His rivalry with Goku and his own Saiyan pride would add an interesting dynamic, especially when Caulifla is involved. He might be initially skeptical of their relationship and could even challenge Caulifla to prove herself worthy of Goku's attention.
Whis, Beerus' attendant, would also be a good character to include. His calm and all - knowing demeanor could serve as a guiding force. He could offer advice to Caulifla and Goku about their relationship and their power - related matters, and might even have some secrets about the Saiyan race that could further the plot.
Piccolo would also fit well. He has a history of fighting alongside Goku and has a complex relationship with Vegeta. His calm and strategic thinking could add depth to the fanfiction, especially in battles where they need to outwit the opponent.
Caulifla and Goku's relationship in fanfiction could be really interesting. Maybe in this fanfiction, they start as rivals. Caulifla, with her Saiyan pride, wants to prove she's stronger than Goku. But as they fight more, they begin to understand each other's fighting styles and develop a mutual respect. This could lead to some really cool training sessions where they both learn new techniques from one another.
Their powers could combine in a fusion. Just like how Goku has fused with Vegeta in the past, he could potentially fuse with Caulifla. This would create a new and extremely powerful warrior. Their combined Saiyan powers along with their unique fighting styles would make for an unbeatable force.
Vegeta would be a great addition. His long - standing rivalry with both Goku and Frieza adds a lot of drama. Also, Beerus, the God of Destruction. His power level and unpredictable nature would shake things up in a story with Goku and Frieza. And Bulma could be included for her technological expertise, which could be useful in creating devices to counter Frieza's advanced technology.
A plot could involve Caulifla being from a parallel universe where she is the only survivor of her race. Goku meets her during a multiverse tournament and decides to help her. As they train and fight side by side, they develop a deep bond that goes beyond friendship and they explore their new relationship while facing various challenges from other universes.
Maybe a fanfiction where Caulifla develops feelings for Goku during their training sessions. However, Goku, being oblivious as he often is, doesn't notice at first. Caulifla tries to prove herself to Goku by constantly challenging stronger opponents. Their relationship could be a mix of friendship and the start of something more, with a lot of action-packed scenes in between.
They could have a friendly sparring match. Goku is always up for a good fight, and Caulifla would be eager to test her skills against him. It would be a high - energy battle with lots of fast - paced action and cool power - up moments.
Training under Goku would expose them to a whole new level of fighting. They would get to spar with Goku and other Z - Fighters. This would not only improve their physical strength but also their combat strategies. They might even develop new techniques inspired by Goku's fighting style. And they could bring back what they've learned to their own Saiyan race to help it grow stronger.
At first, Caulifla might be a bit intimidated by Goku's power. But as they train together, she would start to understand his techniques and philosophy of fighting. Goku would also learn from Caulifla's unique approach to battles. Their relationship could evolve into a deep bond where they rely on each other in tough battles. For example, Goku could save Caulifla from a near - death situation, and in return, Caulifla could come up with a creative battle strategy that helps Goku against a difficult opponent.
Well, it's highly unlikely. Goku is mainly focused on fighting and protecting the universe. His relationship with Caulifla is more of a mentor - student kind of thing in terms of fighting skills. There's no real indication in the series that there could be a romantic love story between them.