There are many Naruto DBZ crossover fanfiction stories but so far I have not come across a Goku x Kushina pairing with Goku being the one from the end of DBZ.
This challenge requires the author to write a story with Goku( from the end of dbz) being transported to the narutoverse somehow. He is also de-aged somehow but keeps all his transformations as they are.
He reaches Konoha at the same time as Kushina. The pairing should be Goku X Kushina strictly and no harem as I think no one wants to share their loved one with some other person and Kushina would never allow such a thing.
Another scenario can be that Kushina survives the sealing of kyuubi and raises naruto and Goku is teleported to the Narutoverse after a foe stronger than whiss destroys the solar system.
Battle of Gods and Resurrection of F have to be considered canon.
The powers of both universes must be made balanced, for example, Goku would need the super saiyan god super saiyan transformation to battle Kaguya at full power though it will easily overpower her.
Goku must have all his transformations from Super Saiyan to Super Saiyan God Super Saiyan. Though, he will have to unlock his powers once again by training.
Kaioken would be equivalent to sage mode,super saiyan should be equivalent to kyuubi chakra mode,ss2 should be equivalent to tailed beast mode, ss3 should be equivalent to sage chakra enhanced tailed beast mode, super saiyan god equuvalent to six path sage mode and super saiyan god super saiyan greater than six path sage mode and kaguya full power.
I hope somebody will take this challenge and produce a beautiful piece of fanfiction.
Best of luck to anyone who might take up this challenge in future. Please inform me if someone decides to write about it as I would like to read it.
Thanksssssss