I agree on Miroque; state clearly sources for any non-canon or any weirder sourcebook stuff in charsheet (either in sheet or in the post where you link or post charsheet to add sort spoiler tag where you reveal what you got). It helps also me clarify 'can you do this?' lot quicker or if anything weird stands out. Anycase you can possess the floor, it's not warded against incorporeal intrusion. Also you can indeed sense change on your ability stats but if it's not ability dmg it's not 'aggressive' sort feeling. Example as wisdom drops it feels more getting drunk or suddenly head clouded gently (more so when it's not permament effect) than feel 'my sanity is drained!'. Ofc Orro can suspect in healthy paranoia has he been affected spell, drug or a curse by someone. As he has not taken any drink nor he is regular drug user.