Naruto might adapt by seeking out other ghouls who have a different view on eating humans. He could form alliances with them and learn from their ways of surviving without causing harm. Also, he could use his ninja stealth to hide his ghoul identity from those who would hunt him.
He could start by learning to control his new powers. Naruto is used to training hard, so he'd likely focus on mastering his kagune and other ghoul - related abilities. This would help him not accidentally harm anyone.
To adapt as a ghoul, Naruto would need to change his diet. Since he wouldn't want to eat humans, he could explore options like eating ghoul - made artificial flesh or finding some sort of magical or scientific solution to his hunger. His strong will and determination from his ninja days would help him in this difficult transition.
To adapt to being the Mandarin, Naruto would first need to understand the nature of the ten rings. He might start by experimenting with each ring's individual power. He'd then figure out how to combine these powers with his existing ninja abilities like rasengan. His relationships with other characters would also change. Some might be afraid of his new power, while others would see it as an opportunity to fight against greater threats. Naruto would have to convince them that he can be trusted with this power and that he'll use it for the greater good.
Well, Naruto has always been adaptable. In a Hive fanfic, he'd first try to communicate with the locals. His positive attitude would make it easier for him to get along. He could use his ninjutsu to his advantage, like using his transformation jutsu to blend in or gather information. He'd also be excited to learn new things in the Hive, which would further his adaptation process. His goal - setting nature would make him look for ways to improve the Hive or help those in need there.
Naruto would first have to adapt to the different magic system. Since he's used to chakra, understanding the arcane, fel, and nature magic in Warcraft would be a challenge. But he's a quick learner. He might start by observing the mages in the world. Also, he'd need to adapt to the new races. He'd probably be curious about the elves, dwarves, and orcs, and try to make friends with them using his friendly and outgoing nature.
It could be Naruto himself. He has a strong sense of justice and is always ready to face new challenges. His ability to adapt and learn quickly would make him a great protagonist in a world filled with ghouls.
Harry Potter would have to adapt to being the Flash in several ways. Physically, he'd need to train his body to handle the extreme speeds. This might involve exercises to strengthen his legs and improve his balance. Mentally, he'd need to deal with the disorientation that comes with moving at such high velocities. He'd also need to figure out how to use his new speed in combat. In the wizarding world, he's used to dueling with spells, but as the Flash, he could use his speed to dodge spells and then quickly counter - attack. He might also need to learn how to use his speed to travel between different magical locations more efficiently, like apparating but much faster. Additionally, he'd need to adapt his relationships with others. His friends might expect him to use his speed for various tasks, and he'd have to decide when and how to use his powers without over - relying on them.
A Naruto character would first have to understand the concept of the Force. For example, Naruto himself might initially struggle as he's used to chakra. But his determination could help him adapt. He might use his skills in combat, like his shadow clones, in a new way within the Sith Warrior framework.
For Naruto to adapt to Hogwarts in a fanfic, he'd start by using his existing skills. His physical training as a ninja would give him an edge in things like flying on broomsticks or dueling. He'd have to learn to control his loud and boisterous nature as Hogwarts has its own decorum. But his ability to see the good in people would make him popular. He'd also have to get used to the idea of different houses and rivalries, which is different from his experience in the ninja villages. Over time, he could blend in and even bring some ninja - like innovation to the Hogwarts way of life.
Naruto could adapt by using his strong willpower. He has faced many challenges in his own world, so he would rely on that experience. He might start by learning about Shao Kahn's powers and the politics of Outworld. His ability to make friends quickly could also help him. He could form alliances with some of the more reasonable characters in Outworld who were previously afraid of Shao Kahn.
Gohan's adaptation in the Naruto world in this fanfic would be a complex process. He would be faced with a world full of new rules, new powers, and new people. At first, he'd be confused, but his intelligence would help him. He'd study chakra, the most fundamental part of the Naruto world. He might also be intrigued by the different jutsu and try to incorporate some of the principles into his own fighting style. Socially, he'd have to learn the ways of the ninja, like their loyalty to their villages. Over time, he could become an important part of the Naruto world, using his Saiyan abilities in new and unique ways that blend with the ninja way.
One way Naruto could survive is by using his Jinchuriki powers. Even in a tortured state, he might be able to draw on the power of the Nine - Tails to heal himself or resist some of the more severe forms of torture. Also, his training with Jiraiya and others has made him physically and mentally tough. He could use the skills he learned, like the Rasengan, in a defensive way if the torturers get too close. His memories of his friends and the promises he made to them would act as a psychological shield against the continuous pain.