Tanjiro might use his sense of smell to detect hidden threats. Since his sense of smell is super - enhanced, he could sniff out any demons or traps in the way of saving Rengoku. For example, if there are demons disguised as allies, Tanjiro would be able to tell by their scent.
Tanjiro and Giyuu have a sort of mentor-student relationship. Giyuu offers guidance and support to Tanjiro on his journey, and Tanjiro learns valuable lessons from him. They also develop a sense of camaraderie as they face the challenges of the demon world together.
The concept of a 'tanjiro sex nezuko comic' is concerning. It may stray far from the intended character portrayals and storylines, and could cause harm or negative impacts.
One common theme is the exploration of gender roles. Since Tanjiro is male in the original, making him female in fanfic allows for a look at how she would be treated in the demon - slaying world as a female. Another theme is new relationships. For example, how she might interact differently with other characters like Zenitsu or Inosuke as a female.
Another theme is mentorship. Shinobu, being more experienced, often acts as a mentor to Tanjiro. She imparts her knowledge about demons and fighting techniques. This is seen in quite a few fanfictions where Tanjiro looks up to Shinobu for guidance.