Board Thread:Theories and Speculation/@comment-1872728-20200725151448/@comment-39120356-20200726164059

I would propose (purely based on definition) someone who can utilise natural chakra to perform a specific task or Jutsu would be 'senjutsu chakra user', and someone who can activate sage mode to augment all of their abilities would be a 'sage mode user'.

However, I personally believe that there are no differences, meaning they're synonymous. My main reason being that I can't remember an instance where either the anime or manga actively differentiated the two of them.

As far as my memory serves, they were used interchangeably to refer to the direct intake of ambient 'nature' chakra while not dying in the process. Jiraiya was an 'imperfect' sage compared to Naruto, because his balance of the chakra was flawed, meaning he was at greater risk of the technique killing him. 'perfect' in this context would simply mean having zero chance of the technique killing you, which we could assume Naruto has.

Another interpretation is that a 'perfect' sage refers to the amount of power you gain from the technique. Jiraiya's sage mode was weaker than Naruto's, so it stands to reason that when they call Naruto a 'perfect' sage, they mean that he is able to use the technique to its fullest potential.

As a response to the original thread, I believe the markings on someone's face are purely an aesthetic choice by the author. Whether or not they actually have a representation to the power level, skill or type of senjutsu the user possesses is completely unknown. It's fair to say each person has their own colour/shape though, so I'd actually reference the different colours and designs of Susanoos. That is to say, either it has a function we don't know about, or it's simply a design choice.