There are indeed alternatives. Some fanfics might explore the relationships between Naruto and other characters in the Blood Prison context. For example, they could depict how Naruto interacts with the guards or other prisoners in a way that promotes the values of the Naruto universe, such as perseverance, loyalty, and friendship. It's important to avoid the offensive ones and seek out the positive fan - created stories.
One possible storyline could be that Naruto is framed for a serious crime within the Blood Prison. The corrupt prison system then subjects him to various forms of torture and unfair treatment, which eventually lead to his death. Maybe he was protecting someone else inside the prison and took the fall for a crime he didn't commit.
One positive theme is Naruto's determination. In many fanfics, he shows unwavering resolve to overcome the challenges of the Blood Prison, whether it's dealing with the strict rules or facing powerful enemies.
One possible plot could be that in this crossover, Female Naruto is in a world where she has to protect her child from an unknown enemy. Maybe it's a new villain from another universe. She would use her ninja skills, which are already quite powerful, but with the added motivation of protecting her child, she becomes even more fierce. Her child could also inherit some unique powers, either from Naruto or from the other universe in the crossover, creating an interesting dynamic as they both try to survive and thrive in this new situation.
The warden of the Blood Prison could be the main antagonist. He might be a power - hungry and corrupt individual who sees Naruto as a threat to his control over the prison. So, he devises plans to get rid of Naruto, which ultimately lead to Naruto's death.
Well, one possible plot could be that Deadpool somehow gets transported into the Naruto universe and ends up in the Blood Prison. Maybe he teams up with Naruto who is also trapped there. They could fight against the prison's corrupt system together and use Deadpool's crazy combat skills along with Naruto's ninjutsu.
Deadpool could be a wild card in the Blood Prison. He might use his regenerative abilities to survive the harsh conditions. For example, he could take on the prison guards without much fear of getting seriously hurt. His unpredictable nature would also throw off the normal order in the prison.
One idea could be the main character having to protect the harem members within the dangerous Blood Prison setting. Maybe there are secrets about the prison that only the harem members know, and they rely on the main character to uncover them while fending off other threats.
Naruto himself could be a likely main character. Given his determination and his ability to make friends, it would be interesting to see him in a harem situation within the Blood Prison. He could use his ninja skills to protect the harem members and try to break free from the prison's mysteries.