He could survive through his strong will and Occlumency skills. By blocking Voldemort from fully penetrating his mind, he can keep his most important secrets safe and hold on to his sanity, which is crucial for survival.
Snape might have some hidden magical artifacts or spells that he uses to protect himself during the torture. For example, he could have a charm that lessens the pain or a talisman that absorbs some of the dark magic Voldemort is using against him.
One idea could be that Snape endures the torture while secretly passing on vital information to the Order of the Phoenix through a magical link. Another could be that his past with Voldemort is explored during the torture, like how he first got involved with the Dark Lord and his internal struggle between loyalty to Voldemort in the past and his newfound loyalty to Dumbledore.
One great fanfiction on this topic is 'The Dark Trials of Snape'. It really delves into Snape's inner turmoil as he endures Voldemort's torture. The author does an excellent job of portraying Snape's complex emotions and his unwavering loyalty to Dumbledore even in the face of such horror.
He survives through his strong willpower. Harry has always been a determined character, and that could help him endure the torture.
One interesting fanfiction could be 'The Unlikely Bond'. In this, Voldemort's care for Snape might be a strategic move at first. He realizes Snape's value in spying on Dumbledore and the Order. As time goes on, it becomes a complex relationship where Voldemort starts to actually care in his own twisted way. It shows a different side of both characters and how power dynamics can shift in unexpected ways.
Snape might endure the punishment in stoic silence. He is a complex character and often used to hiding his true emotions. So, he could just grit his teeth and bear it, all the while plotting his revenge or a way to get out of the situation.
In some fanfictions, Snape might be working with Voldemort because he has been blackmailed. Voldemort could have found out some deep, dark secret about Snape and is forcing him to cooperate. This could be related to Snape's past or something he has done that he doesn't want to be made public.
In these fanfictions, Snape often becomes more self - reflective. He starts to realize the full extent of his actions and how they've affected others. For example, he might come to see how his treatment of Harry was unfair. He also becomes more open about his emotions, which was something he always hid before.
There's a fanfic where Snape takes advantage of a power struggle within Voldemort's ranks. He poisons Voldemort's drink during a meeting, which causes Voldemort to become severely ill, an injury in a sense. Snape does this to try and disrupt Voldemort's plans and give the Order of the Phoenix more time to prepare their defenses.
Power. Voldemort might see Snape as a means to gain more power. Snape is highly intelligent and skilled in the Dark Arts. By caring for him, Voldemort could be ensuring that Snape remains loyal and continues to use his skills for Voldemort's benefit.
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.