One possible main plot could be that the protagonist, who has been a devout follower of a particular goddess in the Danmachi world, discovers that the goddess has been using him or her for her own selfish gains. This realization shatters the protagonist's world, and they then decide to break free from the goddess's influence and find their own purpose.
Maybe the main plot involves a group of adventurers who are betrayed by the goddess they worship. The goddess abandons them in a dangerous dungeon, leaving them to fend for themselves. As a result, they must learn to rely on each other and their own skills to survive and then seek revenge or justice against the goddess.
A 'Betrayed by Goddess Danmachi Fanfic' might explore themes of disappointment and disillusionment. It could center around a character who has put their faith in a goddess in the Danmachi world but is then let down. Maybe the character was expecting protection or special treatment from the goddess but instead gets the opposite. This could lead to interesting character development as they struggle to come to terms with the betrayal and find a new path in the dangerous world of Danmachi.
Well, it could be about Bulma being betrayed by a close friend in the Dragon Ball universe. Maybe that friend reveals her secrets to an enemy, like her latest inventions or the location of the Dragon Balls she was guarding. This would put her in a dangerous situation and lead to a series of adventures where she has to fix the mess.
In the '4 kunoichi gets betrayed fanfic', it could be that the four kunoichi are working for a noble cause. However, one of their own, due to jealousy of the attention the others get, decides to betray them. She spreads false rumors about them, making the whole ninja community turn against them. The four kunoichi have to prove their innocence and also figure out a way to deal with the traitor within their group.
It could also be a misunderstanding. Hinata might be under some sort of mind - control or false impression. For example, an illusion is cast on her that makes her believe Naruto has become evil. As a result, she takes actions against him that he perceives as betrayal. In this case, once the truth is discovered, they would likely reconcile.
It could be that Ash discovers some sort of secret about Harrison that he misinterprets. Instead of talking to Harrison about it, he takes actions that seem like a betrayal. For instance, Ash might tell others about this secret, thinking it's for the greater good, but it actually causes a lot of harm to Harrison.
Maybe the gods are jealous of Naruto's ability to inspire people. In this fanfic, they could use their divine powers to make it seem like Naruto has committed heinous crimes. His village would turn on him, and he'd be on the run. Along the way, he might discover some ancient power that can counter the gods' treachery and use it to clear his name and get revenge on those who wronged him.
In such a fanfic, perhaps Ash and Paul were on a journey together in the Pokémon world. They might be part of a team for a big tournament. Then, one of them could make a deal with a rival group behind the other's back for personal gain, like getting access to a rare Pokémon. This would be the betrayal.
One possible plot could be that Tsunade is misled by false information about Naruto. Maybe some powerful enemy fabricates evidence that Naruto is a threat to the village. Tsunade, believing this, exiles Naruto. Naruto, feeling betrayed, then has to prove his innocence while also facing external threats.
One possible plot could be that Kushina is somehow influenced by an evil force. This force makes her believe false things about Naruto, like he's a threat to the village in the future. So, she betrays him by revealing his secrets or trying to harm him. Maybe she spreads lies about him which turns the villagers against Naruto even more.
Perhaps in this fanfic, Naruto is forced to make a choice between his ninja values and the Jedi code. He might choose something that the Jedi don't agree with, like using his chakra in a way that goes against their light - side - only beliefs. The Jedi then shun him, making Naruto feel betrayed. He might then try to find his own path, separate from both the ninja world and the Jedi order.