Gohan should be in the crossover. He has his own power as a Saiyan and his intelligence. He could come up with strategies to deal with Frieza. Android 18 would also be a good choice. Her strength and lack of emotions in the face of danger could be a contrast to Goku and Frieza's more passionate natures. And Krillin, Goku's best friend, could add some comic relief while also being a valuable fighter in the story.
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.
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.
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.
One great 'Dragon Ball Frieza Fanfiction' is 'Frieza's Redemption'. It explores a different side of Frieza where he tries to atone for his past sins. It's interesting to see how the author develops his character in a new way, away from his typical villainous role.
Cell would be a great villain to include. His ability to absorb other beings and his complex personality make for an interesting dynamic with Goku and Gohan. There could be a scenario where Cell somehow returns and is even more powerful, forcing Goku and Gohan to team up again in a new and intense battle.
Sly Cooper would be a great addition. Sly's sneaky, thieving skills could add an element of stealth to a Spyro crossover. He could help Spyro steal back a precious artifact that has been stolen by their common enemy, using his lock - picking and acrobatic skills.
One interesting plot idea could be that Frieza somehow manages to gain new powers on a distant planet and returns to challenge Goku again. But this time, instead of just brute strength, he uses cunning strategies. Another could be a scenario where Goku and Frieza are forced to team up against an even greater threat from another universe. This would be a great chance to explore their complex relationship.
Definitely Vegeta. His prideful and complex personality would add a lot to any crossover. For example, in a crossover with the Avengers, his initial reluctance to work with Earthlings could create interesting conflict. Another good character is Piccolo. His wisdom and fighting skills would be valuable in a crossover. If it was a crossover with the Mortal Kombat universe, Piccolo could hold his own against the likes of Scorpion and Sub - Zero.
Trunks is also a great choice. He has his time - traveling aspect which could be used in really creative ways in a crossover. For instance, in a crossover with the Terminator universe, Trunks could team up with the resistance against the machines, using his time - traveling knowledge and his sword skills.
Well, in addition to the main Dragon Ball Heroes like Xeno Goku and Xeno Vegeta, characters like Gohan could be great. His potential as a half - Saiyan is always interesting. From other franchises, Ichigo from Bleach could be included. His ability to use a sword and his Hollow powers would be a fresh addition. And of course, Spider - Man from the Marvel Universe. His quippy nature and his acrobatic fighting style would create some really fun interactions with the Dragon Ball Heroes.
I really like 'A Frieza Race Warrior's Journey'. In this fanfiction, it focuses on a young Frieza race member who tries to break free from the traditional ways of his race. He wants to find a new path that doesn't involve all the destruction and tyranny that the Frieza race is known for. It has some great action scenes and character development.