If someone had their Sun in my 12th, it would make excellent aspects to nearly every part of my chart. However.. I just don't like it. I find this aspect deeply unsettling. I never really feel like I "know" this person, and always end up finding something shocking about them that blindsides me. Generally I find myself a good reader of people but that trait tends to get really murky with 12th house personal planets.
Two Suns and a Moon comes to mind.. just not a fan
Might be because I have an empty 12th house though (even though my chart is Pisces/Neptune heavy)