If Goku were in the DC Universe in a fanfiction, it would be really interesting. He might form an alliance with Superman. They both have a strong sense of justice. But their fighting styles are quite different. Goku's martial arts skills combined with Superman's super - powers could make for an unbeatable team against the likes of Darkseid or other major threats.
Well, with Ultra Instinct, Goku would be able to react extremely quickly to the DC heroes' powers. For instance, when facing Flash, who is super fast, Goku in Ultra Instinct might be able to match his speed or even anticipate his moves better. This could lead to a mutual respect between them as they test each other's limits.
His father might be extremely proud. After all, Goku has achieved so much, like protecting the Earth multiple times. He would look at Goku with admiration for his strength and kindness.
When it comes to comparing Goku's powers to DC heroes in a fanfiction scenario in the DC Universe, it's complex. Against Flash, Goku has his own kind of speed. While Flash uses the Speed Force, Goku can move at incredible speeds through his own ki - based powers. In terms of raw power, Goku might be on par with or even stronger than Superman in some aspects, especially when he reaches his higher forms like Super Saiyan Blue. However, Superman has his own unique abilities like heat vision and freeze breath that Goku doesn't have.
Gohan would be really surprised, but being the kind - hearted person he is, he would try to understand and help out. He could offer to train with them in a more gentle way to keep them fit during the pregnancy. Piccolo would be more of a silent observer, but still be there in case of any threats.
The reaction among fans would be quite mixed. Some die - hard fans of the original series would be appalled as they have a clear image of ChiChi and Goku's relationship. They would see this type of fanfiction as a perversion of the original concept. On the other hand, there are those who are more open - minded and might see it as an interesting, if not controversial, exploration of the characters. But overall, the negative reactions would probably outweigh the positive ones.
Goku would be a mix of angry and worried. His Saiyan blood would make him want to rush into battle with Raditz right away. But he also knows how dangerous Raditz is, so he might first try to gather some allies, like Piccolo. He'd be constantly thinking about Gohan and how to rescue him as quickly as possible.
One idea could be Goku ending up in the DC universe and having a friendly spar with Superman. Their different power sources and fighting styles would make for an exciting encounter. Maybe Goku learns about Kryptonite and how it affects Superman, which gives him a new perspective on weaknesses.
Goku would likely be extremely excited. He has always had a longing to know more about his Saiyan heritage and his father. Meeting Bardock would be like a dream come true for him. He'd probably ask a million questions about his past and Saiyan culture. Chi - Chi, on the other hand, would be a bit more reserved at first. She'd be polite but also a bit cautious, as she doesn't know what this Saiyan from Goku's past might be like. But as she sees Goku's joy, she'd warm up to Bardock.