1) Average to the point of invisibility:
Aenon is not magic in anyway nor has he the ability to turn himself invisible, nothing so interesting.
If fact it is the reverse, he is so un-interesting, so average and without note that he can go through a crowd and not be noticed by anyone. He is a background character, an extra of an extra in the play of life. So in turn he could in theory go places that people would normally not have access but not due to any great skill or care of his, people just do not care. He could walk into a military base and people would assume he was there to fix the slight slant on the map table or the shelf that does not sit quite right. This lack of notice could in theory extend to combat as people are not threatened by a nobody and certainly not a nobody with an eating utensil. For example if he and a group of people were to be attacked by bandits, he would likely be the last one to be attacked and even then he could likely wander off in the confusion and no one would be any the wiser.
He would just feel bad for doing so.
This of course is no advantage in a one on one combat as if there is no one else to distract his ‘opponent’ from his lack-lustre presence then they will still be aware of said presence, unless something more interesting (pretty much anything) were to occur.