Thinking about the different abilities we've seen in the series:
Deidara Hands
Kakuza's tendril body
Kisame
Naruto whiskers
Could it be plausible to suggest that these are genetic defects which enhanced the users based on the fact that they have a chakra network to support or strengthen that defect?
Deidara Hands
Kakuza's tendril body
Kisame
Naruto whiskers
Could it be plausible to suggest that these are genetic defects which enhanced the users based on the fact that they have a chakra network to support or strengthen that defect?