La Santa Muerte is often associated with folk religion and has various beliefs and tales attached. Some see it as a protector, while others have different interpretations. It's a complex and diverse story.
The exploration of the afterlife is also a frequent theme. Since Santa Muerte is associated with death, novels might take readers on a journey through different realms of the afterlife. Also, themes of justice and vengeance can be found. Santa Muerte is sometimes seen as a figure who can dispense justice, so characters might seek her help for revenge or to right wrongs.
Well, one way could be in their physical abilities. Maybe in the fanfic, Naruto is shown to have some of Zetsu's stealthy movement skills, like being able to blend into the environment in a similar way. Another similarity could be in their connection to nature. Zetsu has a strong link to the plant - like aspects of nature, and Naruto's chakra might be shown to have a similar kind of connection in the fanfic.
One popular 'Santa Muerte' fantasy novel could be 'Santa Muerte: The Saint of Death' which delves into the unique mythology surrounding the Santa Muerte figure. It weaves a tale of mystery and the supernatural, exploring her role in a fictional world filled with magic and intrigue.
I'm not sure specifically as there could be many different interpretations in fanfiction. But it might involve Zetsu using his unique abilities to rescue Naruto from a dangerous situation, like a powerful enemy attack or a life - threatening trap.
A third theme could be growth. They both start from certain points in their characters and develop over the course of the fanfic. Tobi might become more serious or Zetsu might open up more, depending on the plot and how the author wants to develop their relationship.
One main theme is loyalty. Given their relationship in the Naruto series, fanfictions often explore how loyal they are to each other and their common goals.
In a fanfic where Naruto is trained by Zetsu, the story could take an interesting turn. Zetsu has knowledge of the Akatsuki and their secrets. Naruto could learn about the organization from the inside out. This knowledge could help him in his quest to bring peace. He might also gain some physical enhancements. Zetsu is quite durable in his own way, and Naruto could inherit some of that sturdiness. This would make him an even more formidable opponent in battles against strong foes like Pain or Madara.