One possible reason could be a curse. Maybe a dark wizard placed a curse on Harry that not only changed his eye color but also had some other negative impacts on his magic or personality. For example, it could be a curse that slowly drains his power while making his eyes red as a visible sign of the curse's presence.
In the fanfiction, his red eyes might be a sign of a hidden heritage. Maybe he has some unknown family connection to a powerful magical being that has red eyes as a characteristic. This could open up a whole new plotline about his true identity and his place in the wizarding world.
One reason could be to create a unique and unexpected story. By introducing a non - magical, real - world illness like lung cancer into the magical world of Harry Potter, the author can explore how the characters would react. Another reason might be to show the contrast between the muggle world, where such diseases are common, and the wizarding world, which has magic to deal with most problems. Maybe the author has some personal experience related to lung cancer and wants to incorporate it into a story they love.
Well, in fanfiction, red eyes on Harry Potter could be a sign of a new magical power. Maybe it's related to some dark magic he accidentally got involved with, like a curse that gives him this strange feature but also some unique abilities. For example, it could be linked to the ability to see through certain spells or illusions.
One possible plot could be that Harry Potter loses his eyes in a dark magic encounter. His friends then have to help him navigate the wizarding world in a new way. Hermione might use her vast knowledge to create magical aids for him, like spells that create a sort of echolocation. Ron would be by his side, providing emotional support and physical protection when needed.
One reason could be a powerful dark magic spell cast upon him by a new villain in the fanfiction world. This spell might be designed to make him disappear from the wizarding world entirely.
One possible reason could be that a powerful dark magic spell has been cast on him. Maybe a new dark wizard or witch, created specifically for the fanfiction, has found a way to make him vanish to cause chaos in the wizarding world. Another reason might be that Harry has chosen to disappear himself. Tired of the constant attention and danger, he decides to go into hiding, perhaps using some long - forgotten magic or a powerful magical object to conceal his presence.
It could be a very strange and creative fanfiction where characters in the Harry Potter universe have buttons instead of eyes. Maybe it's a dark or comical take on the characters, with the button - eyes adding an element of the uncanny or the absurd.
It might be due to some sort of bloodline fusion. Naruto is known for his Uzumaki heritage, but perhaps there was an unexpected encounter with another clan's power that merged with his own, and as a result, one of his eyes turned red as a new and unique ability emerged.
A possible reason could be a magical transformation. For instance, he might encounter a powerful magical artifact that alters his appearance, giving him red eyes as a side - effect. This transformation could be a key part of a new adventure where he has to learn to control this new aspect of himself.
Maybe he's curious about different interpretations of his own story. In fanfictions, his character might be in new and exciting adventures that the original books didn't cover.
One possible reason could be that he has been through so much in his original adventures that he's just tired. He might feel like he's constantly being put in new, often contrived, situations in the fanfiction and he simply wants to step away from all the chaos and drama.