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.
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 a straight - up power comparison, Goku has the ability to reach extremely high power levels that can destroy planets. But Naruto has the power of the Nine - Tailed Fox and his Sage of Six Paths mode which also gives him immense power. If the fight takes place in Naruto's world, Naruto could use the environment to his advantage, like summoning giant toads or using the terrain. On the other hand, if it's in a more open space like in Goku's battles, Goku could use his flight and long - range attacks more effectively. So it's hard to say who would win definitively.
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.
His presence can add an emotional depth. It could be a moment of connection between father and son, even if Goku doesn't know Bardock is there. It might also serve as a reminder of Goku's Saiyan heritage.
In a one - on - one fight between One Punch Man (Saitama) and Goku, it's really tough to say. Saitama is known for being able to defeat any opponent with just one punch. However, Goku has a vast array of powerful forms and techniques. If Saitama landed his first punch, he'd win instantly. But Goku's speed and ability to constantly power up could potentially give him an edge. He could keep dodging Saitama's punches until he found a way to overpower him. It really depends on how the fight is set up in the fanfiction.
Kid Buu is a very powerful and chaotic villain in Dragon Ball FighterZ. In the story, he is extremely destructive. He has a very simple and brutal nature, just wanting to cause chaos and destruction everywhere. His power level is off the charts, and he gives the Z - fighters a really tough time.
One key event is Kid Buu's destruction of many planets early on. Another is when Goku and Vegeta fuse to try and take on Kid Buu. Also, the moment when the Z - fighters come up with a final plan to defeat him is important.