In the fanfiction, Bardock might be in a state of awe. Goku's fight against Buu is no small feat. Bardock would likely note Goku's ability to keep getting back up, no matter how hard Buu hits him. He might also be thinking about the power levels involved. In his time, the power levels he knew were much lower. Now, seeing Goku take on a foe as powerful as Buu, he'd realize just how much the Saiyan race has evolved, especially with Goku as a prime example.
In the fanfic, Bardock might be filled with pride. He could be thinking how his son has grown into such a powerful warrior. After all, Goku has come a long way from being a little Saiyan baby sent to Earth. Watching Goku fight Buu, Bardock might see all the potential he always knew Goku had, finally being fully unleashed.
It could potentially influence Goku's fighting style. Bardock was a fierce warrior with his own set of techniques. Goku may subconsciously incorporate some of Bardock's fighting spirit or even mimic some of his moves. Also, Bardock's presence could be a source of inspiration for Goku, making him come up with new strategies on the fly during the fight against Buu in the fanfic.
At first, it might be tense. Bardock is a hardened Saiyan warrior from a different era, and Goku has grown up on Earth with a very different set of values. But as they start to communicate, they would find common ground in their Saiyan blood. Goku's pure - heartedness could gradually win over Bardock, and Bardock's strength and pride could earn Goku's respect.
At first, it could be a bit rocky. Bardock is used to the harsh Saiyan ways, while Goku has been raised on Earth with different values. But as they spend time together, they start to understand and respect each other. Bardock could become a mentor to Goku, teaching him advanced Saiyan fighting techniques and Goku could teach Bardock about friendship and love.
One possible interaction is that Bardock could spar with Goku and Gohan. He'd test their limits and see how much they've learned about fighting. Another could be Bardock sharing stories of Planet Vegeta with them, which would be really interesting for Goku and Gohan to hear.
Goku would likely win. He's got insane power and combat skills that might give him the edge.
Goku would likely win. He has powerful techniques and determination that could give him the edge over Majin Buu.
It's hard to say for sure. Both Goku and Majin Buu have unique abilities and strengths. But Goku's determination and experience might tip the scales in his favor.
I think it depends on various factors. Goku's potential is immense, but Bardock's raw strength and fighting spirit shouldn't be underestimated. Maybe it would come down to a strategic move or a sudden burst of power.
In the manga, it could go either way. Goku has his unique skills and transformations, while Vegeta is no slouch either. Kid Buu's raw power and unpredictable nature make it a very close call.