Well, Gamabunta is a very iconic character in Naruto. In a fanfiction involving oil, it might be that the oil is something that Gamabunta has to deal with in an unusual situation. For example, if there's an enemy who uses oil - based attacks or if there's a place filled with oil that Gamabunta has to traverse. It could also be that the fanfiction writer is exploring a new aspect of Gamabunta's character by making him interact with this element of oil.
Gamabunta might interact with oil in various ways. He could accidentally slip on a pool of oil if it's used as a trap. Or he could use his size and strength to break through barriers made of oil. Maybe the oil has some magical properties and Gamabunta has to find a way to counteract its effects on him or his allies.
In a snake summon Naruto fanfic, there could be a plot where the snake summons are from a different dimension. These snakes have their own culture and hierarchy. The story could follow a group of ninjas, including some of the main characters from Naruto, as they explore this new dimension through their connection with the snake summons and have to deal with the political and power struggles within the snake society.
One possible fanfiction could be about a new character in the Naruto universe who discovers a unique way to summon Scorpions. They might use these scorpions for combat or for gathering information. For example, the character could be from a hidden village that has a special connection to scorpions, and they use this to their advantage in battles against other ninja.
One possible fanfic could involve Shirou using some kind of magic or special ability to summon Naruto. Maybe Shirou is in a difficult battle and needs Naruto's strength. Naruto could arrive with his signature orange jumpsuit and start using his shadow clone jutsu to turn the tide of the battle. It would be an exciting crossover of the Fate and Naruto universes.
One possible fanfic could involve Raven using some sort of dark magic or special jutsu to summon Naruto from his own world to hers. Maybe she needs his help to fight off an evil force in her realm that her own powers are insufficient to defeat. Naruto, with his never - give - up attitude and powerful ninjutsu, could bring a new dynamic to Raven's world.
Well, having all the summoning contracts might also be a burden. He has to manage and keep good relations with all the different summon clans. If he fails to do so, he could lose their support. Also, it might be overwhelming to keep track of all the different summons' abilities and needs.
One consequence could be a huge power boost. Naruto would become extremely strong, which might change the power balance in the fanfiction world. Enemies would be more cautious of him, and allies might rely on him more. Another consequence could be the internal struggle. The Kyuubi has its own will, so Naruto might have to constantly fight to maintain control when it's summoned.
A great fanfiction concept could be centered around a group of rogue ninjas who steal the snake summoning contract. They use the summoned snakes for their evil deeds, causing chaos in the ninja world. A young, inexperienced ninja team is then tasked with retrieving the contract. Along the way, they learn about the history and power of the snake summonings, and they also face moral dilemmas when they realize some of the snakes are not as evil as they seem.
Well, it could be about a unique take on Naruto's world where there are special summonings related to aeons. Maybe it involves new characters or abilities that come with these aeon summonings. It's hard to say exactly without reading it, but it might also explore different storylines that the original Naruto series didn't cover.