The face mask could be designed in a way that gives him a more intimidating appearance. If it has some sharp edges or a menacing pattern, it could make Naruto seem like a more formidable opponent. This change in appearance might cause his enemies to be more cautious around him, and his friends might also see a new side of him.
Well, obviously, the addition of the face mask gives him a more mysterious look. His usually open and friendly face is partly hidden, which might make others view him with more caution or curiosity.
Perhaps he is trying to distance himself from his past self. Naruto has had a tough childhood and has been through a lot. Changing his appearance could be a way for him to start anew, to shed the image of the 'troublemaker' or the 'lonely kid'. He might want to present a new, more confident and respected image to the people around him, both friends and foes.
He might become more reserved. Kakashi is often a bit aloof and mysterious, and wearing the face mask like him could make Naruto act in a more subdued way, not showing his emotions as openly as he usually does.
One possible reason could be for disguise. Maybe he is on a secret mission and doesn't want to be recognized easily. In the Naruto world, there are many dangerous foes, and wearing a face mask can help him blend in or hide his identity from those who might be targeting him.
He would probably have a more menacing look. The bat wings would be large and leathery, perhaps a dark color like black or deep brown. His overall silhouette would be bulkier with the wings attached to his back. His clothes might need to be adjusted too, maybe with some slits or special fastenings to accommodate the wings when they're folded.
Perhaps in this fanfiction, there's a specific mission or situation. Maybe they are on a stealth mission together, and Naruto decides to wear a face mask like Kakashi to blend in better or to follow some kind of ninja code that Kakashi has taught him for this particular task.
Well, Naruto with Madara's hairstyle would look quite different. His usually spiky blonde hair would be replaced by Madara's long, dark hair. It might make him look more serious and less of the goofy, energetic Naruto we know. His face might seem more angular with that hairstyle, and it could also give him an air of mystery, like Madara had.
He might become more confident. Without the mask, he no longer has something to hide behind, and this new - found openness could boost his self - assurance.
If Naruto has wings, his hair might seem to flow more gracefully in the wind as he flies. His eyes could glow a different color when he uses the power associated with the wings. Also, the wings themselves could be unique. They might be made of some kind of chakra - like substance, giving them a shiny or translucent look. And there could be markings on the wings that are related to his Uzumaki heritage or some new power he has acquired.
Well, if Naruto had 3 eyes in fanfiction, his visual perception would be greatly enhanced. He could potentially have a wider field of vision, like being able to see in more directions simultaneously. This might give him an edge in battle, as he could detect enemies coming from unexpected angles more easily.