His arrival could have a huge impact. He might introduce new technology or fighting techniques to the Autobots in the past. This could change the outcome of battles they were previously losing. For example, if he shows them a more effective way to defend against a Decepticon attack.
One possible plot twist could be that Optimus discovers he is the cause of an event in the past that he was trying to prevent. For example, his presence might accidentally lead to the earlier awakening of a powerful enemy. Another could be that he meets a younger version of himself and has to convince his past self to trust him without revealing too much about the future.
His sense of purpose might also change. In his original time, he might have been fighting for a certain cause. But in the past, he could discover new things to fight for or new values to uphold. Maybe he realizes the importance of preserving certain aspects of the past that were lost in his future, and this changes his overall attitude and personality as he becomes more of a preserver than a fighter in some ways.
His super strength could easily disrupt the past. For example, if he's not careful while trying to stop a crime, he might accidentally cause more damage than good. He could break things that were important in the original timeline.
His powers might also influence the people in the past in unexpected ways. Maybe his dark chakra could seep into some characters and start to corrupt them earlier than in the original story. This could lead to new alliances and rivalries forming, completely different from what happened before. For instance, a character who was originally a hero could be turned into a villain because of Dark Naruto's influence.
His super strength could accidentally cause destruction in the past. For example, if he's not careful while saving someone, he might break a building that was historically important. His spider - sense could also give him an unfair advantage in situations where he shouldn't have such an edge, like in a simple street fight in the past.
Naruto's knowledge from the future could have a huge impact. He might introduce new fighting techniques or ways of thinking that were not present in the past. This could change the balance of power among the ninja villages. Also, his actions could influence the relationships between different clans. For example, if he befriends a clan that was previously isolated, it could lead to new alliances and change the political landscape of the ninja world.
Naruto's power of the Nine - Tails would be a major factor. In the past, the Nine - Tails was feared and hunted. If Naruto shows up with the power under control, it could change how people view the beast. His chakra reserves, which are huge because of the Nine - Tails, could allow him to perform feats that were previously thought impossible in the past, like quickly rebuilding a village or fending off a large - scale invasion on his own.
Their powers are quite strong. They could easily overpower many of the villains in the past. This might lead to a quick end to some threats that were difficult to deal with in the original timeline. For instance, if they faced Frieza in the past, they could defeat him without much trouble, changing the course of the Saiyan story.
Naruto's powers, especially his Nine - Tails chakra, could have a huge impact. He could use it to fend off stronger enemies much earlier. Hinata's Byakugan would give her an edge in predicting enemy moves. They could use their powers together to change battles that were originally lost. For example, Naruto could use his Rasengan more effectively with Hinata's support and knowledge from the future.
His water - based powers might be affected in different ways. If he goes back to a time when the oceans were less polluted, the purity of the water could make his powers stronger. However, if he goes to a time when the gods were more in control of the elements, they might be able to limit his power. For example, Poseidon might have more say over how Percy can use water powers if they are in the same time period.