Well, perhaps in this fanfiction, Goku Black makes a fatal mistake. He could underestimate Goku's ability to adapt during battle. Goku, being the experienced fighter he is, notices this weakness and uses it against Goku Black. He might use a combination of his signature moves like the Kamehameha in a new and unexpected way that catches Goku Black off - guard, leading to his defeat.
The story could start with Goku being pushed to his limits by Goku Black's attacks. But then, he remembers his training with the Kai's and how they taught him to focus his energy in a more efficient way. He then uses this knowledge to create a more powerful Kamehameha that breaks through Goku Black's defenses and kills him.
The person who kills Black Noir in the comics is [Character Name]. This happens due to a long-standing feud and a series of circumstances that build up throughout the story. It's a fascinating part of the comic series.
Zamasu is often paired with Goku Black. Since they are closely related in the original story, fanfiction writers like to explore their relationship further. It could be about their shared goals or how they interact on a more personal level.
I think Zeno would be a really tough opponent. Zeno has the power to erase entire universes, and a Goku and Goku Black fusion, despite being extremely powerful, would have a hard time against such a being with god - like powers.
It could be Zamasu. Since Goku Black was Zamasu in Goku's body in the original story, perhaps a more powerful and enraged Zamasu could be the main antagonist. He might be jealous of the new fused form's power and seek to destroy it.
Sasuke could also oppose Black Goku. With his Sharingan and Rinnegan, Sasuke has a wide range of powerful abilities. He is also very intelligent and strategic. Sasuke would likely see Black Goku as a threat to the balance of power in the Naruto universe and would step in to fight him, especially if it involved protecting his friends or the ninja world in general.
Hit would also make for a fascinating pairing. Hit is a skilled assassin with time - manipulation abilities. He could be a great foil to Goku Black. Maybe Goku Black tries to outwit Hit in his time - stop techniques, or they could form a temporary alliance based on their mutual desire to eliminate certain opponents in the tournament. There would be a lot of cat - and - mouse action between them.
In this kind of fanfiction, the power hierarchy in the Dragon Ball universe would be completely shaken. Goku's victory over Beerus could inspire other characters to strive for greater power. New alliances might form, and old ones might break. The Z - fighters could see Goku in a new light, either as a hero or a potential threat. The story could also explore Goku's moral compass. Killing Beerus, a god, might make Goku question the limits of his power and the responsibility that comes with it. There could be a lot of internal and external conflicts that make for an exciting fanfiction.
Well, in the original Dragon Ball series, Beerus is an extremely powerful god of destruction. For Goku to kill him in a fanfiction would be a huge shock. However, in the realm of fanfiction, anything can happen. Fanfic writers often like to explore 'what - if' scenarios that deviate from the official canon. It could be interesting to see how the writer would justify Goku achieving such a feat, considering Beerus' overwhelming power.