A plot might involve Goku accidentally stumbling into Zeno's realm. Zeno, who has only seen beings either fear or revere him, is amused by Goku's lack of fear and his eagerness to spar. So, they start a friendly sparring match that has the potential to either create chaos in the multiverse if they go all out or lead to a new understanding between the two most powerful beings in the Dragon Ball universe.
An interesting interaction could be when Goku, with his straightforward and fearless nature, asks Zeno if he can fight him. Zeno, who is used to being unchallenged, is both surprised and entertained by Goku's boldness.
Goku might run into past versions of his friends. He could see a younger Krillin or Bulma and have some really interesting interactions. He could also meet past versions of his enemies and try to change their fates. For instance, he could meet a young Vegeta and try to steer him away from the path of evil. This would be a huge change in the Saiyan's story.
I'm not sure which specific novel 'King Zeno' is from. There could be many fictional characters named Zeno, and without more context, it's hard to determine who this King Zeno is in the novel.
The significance of King Zeno in the novel can vary greatly. He could be a central figure around which the entire story revolves. His character might represent certain values or ideals that the author wants to convey. For example, if he is a just king, it could be a statement about the importance of fairness in society. On the other hand, if he is a corrupt king, it could be a critique of power abuse. His presence could also introduce political intrigue and power struggles into the novel, making the plot more interesting and engaging for the readers.
It could be Iruka. Since Iruka is an important teacher in Konoha, he might be the first to notice Goku's arrival. He'd probably be cautious at first, not knowing what to make of this powerful being, but then try to figure out if Goku is a threat or not.
In this fanfiction scenario, Goku could meet Bulma when she was a child. He could befriend her in a different way compared to their first meeting in the original story. Also, he could run into King Kai at an earlier time and start training with him much sooner, which would significantly boost his power levels and change the course of his battles in the future.
One idea could be a story where the Grand Priest and Zeno are on a journey through the universes to understand the different cultures. They could encounter various powerful beings and have to make decisions about how to handle them. For example, they might come across a universe where the inhabitants are facing a great danger and they decide to use their powers to help.