It's never separate from actually being a Shadow, so it's a little hard to say. Aigis could sense Shadows and got a really bad feeling from Ryoji (Pharos except older and more human) but couldn't figure out why, but even then Ryoji is still part Shadow.

If we go the Tier 2 route (which might just be easier), what it would mean for Phillip right now is that he'd show up as non-human on other people's radar, if we ever get a Minako (or even Minato) he'll be MORE drawn to her/him than he would have been otherwise, and he'd been drawn to people with negative emotions. After this he'll starting Echoing back some of the lack of caring/emotion that comes from being a little tiny bit human buuuut mostly Shadow, but for now he'll still be cheerful little boy.