Naruto would probably be conflicted. On one hand, he has a deep love for Konoha, his home. But on the other hand, he might have been hurt by the past events that led to his departure. He could initially be hesitant, but eventually be swayed by the thought of seeing his friends again.
Well, it could be that the wielder of the Rinnegan has the ability to control powerful forces like the Six Paths techniques. They might use the Deva Path to create massive gravitational pulls that start to crumble the buildings in Konoha. Or perhaps with the Preta Path, they could drain the chakra from all the ninja in Konoha, leaving them defenseless against further attacks, which eventually leads to the destruction of the village.
One possible reason could be a sense of betrayal. Maybe he felt abandoned or mistreated by Konoha in some way. For example, if he was shunned because of the power within him that others feared.
In this fanfiction, the reception could be mixed. On one hand, the older generation who remembered Minato and Kushina would be very glad to see them return. They were important figures in Konoha's history. But on the other hand, some of the younger shinobi who didn't know them might be a bit cautious at first. Still, once they learn about their heroic deeds, they would likely warm up to them.
Ruby's speed and scythe - wielding skills could be very useful in Konoha. Her semblance of super speed would make her a formidable opponent in combat. She could quickly dodge ninja attacks and surprise her enemies. Her scythe could be seen as a unique and powerful weapon in the ninja world. Weiss's glyphs and ice magic would also be a great asset. She could use her ice to create barriers or freeze enemies in place, which is similar to some water - style jutsu. Her summoning of the Arma Gigas could be a new and powerful addition to the battles in Konoha.
One possible reason could be that Naruto feels betrayed by Konoha. Maybe he discovers some dark secrets about the village that make him lose faith in it. For example, if he finds out that the village elders were involved in unethical experiments or plots against his friends or family, he might not want to help.
It can also make him look more complex. In the original story, Naruto is all about protecting Konoha. But in this fanfic, his decision not to help challenges that simple view. He could be seen as a character who weighs the pros and cons and makes a tough choice, like if he decides Konoha has done too much wrong in the past to deserve his help.
Another way is through his attitude towards the villagers. He would show no respect or kindness to them. Instead, he would be cold and hostile, perhaps even going as far as to physically intimidate those who cross his path in Konoha.
The Hokage, whoever it is at the time, would see Naruto's actions as a major threat. They would likely assemble the ninja forces to defend Konoha. But there would also be a part of them that would wonder what drove Naruto to this. Kakashi, for example, would be conflicted. He has a deep bond with Naruto, but he also has a duty to protect Konoha. So he would try to find a way to end this without harming Naruto too much.
It could also be related to the way Konoha has dealt with other issues like the Uchiha clan massacre. If Naruto discovers some aspects of Konoha's involvement in it that he finds morally unacceptable, such as covering up the truth or being complicit in some way. This could make him lose faith in Konoha and be unable to forgive it.