It could be the village elders. They often make decisions for the benefit of the village as they see it. They might think Naruto is needed back in Konoha to deal with potential threats or to boost the morale of the villagers.
It could also be a new character created specifically for the fanfiction. This character might be an old hermit who has been living in Konoha in secret and is now passing on his knowledge of Fuinjutsu to Naruto or other characters. Maybe he has a special connection to the founding of Konoha and the original development of Fuinjutsu.
Well, in some fanfictions, Naruto might outsmart Konoha by using his unique knowledge of the village's secrets that others don't know. For example, he could use his understanding of the old tunnels under Konoha to his advantage in a situation where he needs to escape or gain an upper hand in a conflict.
Some of the elders in the council are also very hated. They are usually portrayed as being old - fashioned and stubborn. They oppose any new ideas or changes that could potentially disrupt the status quo in Konoha. Their lack of understanding of the younger generation, like Naruto's generation, and their reluctance to adapt to new threats make them disliked in these fanfictions.
It could be Sasuke. If he were to turn to the dark side in the fanfiction, his Rinnegan powers could be used to destroy Konoha. He has the potential to be extremely powerful and if he has some sort of vendetta or is influenced by some dark force, he might take his anger out on the village.
Sakura could be one of the main characters. She has a long - standing relationship with Naruto and might play a role in convincing him to return. Maybe she tells him about the state of the village's hospital or how his friends miss him.
Naruto might forgive Konoha because he realizes that holding a grudge won't solve anything. He has seen the destruction that hatred can cause, like during the Pain arc. So, he chooses to forgive in order to move forward and bring about positive change. Another reason could be his respect for the previous Hokages and their ideals for Konoha.
One possible reason could be fear. Naruto has the Nine - Tails within him, and some in Konoha might be too afraid of its power getting out of control. They may not fully trust Naruto to keep it in check.
Definitely Sasuke. Their bond is such that Sasuke would not stand by and let Naruto destroy Konoha. He has his own reasons to protect the village now. Shikamaru is also a likely candidate. He's intelligent and would quickly figure out that Naruto's actions are wrong. He would use his strategic mind to try and stop Naruto. And Hinata, who loves Naruto deeply, would oppose him in the hopes of bringing him back to his senses.
The traditionalist elders might oppose Naruto. They are used to the old ways of running Konoha and may see Naruto's takeover as a threat to their power and influence.