HOKAY, so Senka here is the goddess of darkness, both literal and metaphorical. On the one hand, this means she can sense if you have affiliations with darkness or use darkness-based abilities. On the other hand, she gets to see all of a person's "darkness" manifested on their person, distorting their appearance in a manner that represents their personal problems. Appearance features can be pretty much anything, canonically she's seen things like spectres following people, horrifically deformed and warped moving bodies, paper-like skin and other similar features on people. That said, the features are more likely than not aren't actually physically there; she only sees them in a meta sort of way. If you're familiar with Persona 4, she basically sees people as Shadows.
I'm leaving it up to the muns to decide on what she'll be seeing specifically but the general rule of the thumb is that the more deep-seated, serious, debilitating etc. their issues/insecurities/problems are, the more prominent they will appear to her. This is especially true if they do not acknowledge or attempt to hide or deny them. It's entirely possible for a person appear completely different to her through this. Go wild guys. Conversely, their appearance can also change over time if they confront/reconcile/come to terms with their issues, and they begin to look more "normal", revealing more of their true appearance to her. Also, it's possible for someone to be close to their true appearance to her if they don't really have any outstanding issues to begin with, or have already dealt with them.
Senka herself won't know everything, particularly the nitty-gritty details, without the benefit of context, but she's been doing this long enough that she generally can figure out what the issues are. That said, she respects privacy and will only bring them up to them personally in private if she decides to meddle, and I will always ask before before she tries!
If you are a special case and happen to qualify as pure light, it will cancel out her Shadow-vision like in canon with her counterpart. Gods and other related beings are exempted as well.
And now a handy form!
I'm leaving it up to the muns to decide on what she'll be seeing specifically but the general rule of the thumb is that the more deep-seated, serious, debilitating etc. their issues/insecurities/problems are, the more prominent they will appear to her. This is especially true if they do not acknowledge or attempt to hide or deny them. It's entirely possible for a person appear completely different to her through this. Go wild guys. Conversely, their appearance can also change over time if they confront/reconcile/come to terms with their issues, and they begin to look more "normal", revealing more of their true appearance to her. Also, it's possible for someone to be close to their true appearance to her if they don't really have any outstanding issues to begin with, or have already dealt with them.
Senka herself won't know everything, particularly the nitty-gritty details, without the benefit of context, but she's been doing this long enough that she generally can figure out what the issues are. That said, she respects privacy and will only bring them up to them personally in private if she decides to meddle, and I will always ask before before she tries!
If you are a special case and happen to qualify as pure light, it will cancel out her Shadow-vision like in canon with her counterpart. Gods and other related beings are exempted as well.
And now a handy form!