OOC Resistance is a trait of canon characters who are only partially vulnerable to a Mary Sue's ability to pull them out of character. Such characters tend to have some idea that they are acting out of character, but are usually unable to stop themselves from complying with the Mary Sue's wishes. This can make things worse for them because they are aware of the horror of being Sued but unable to stop it. Possessed OOC-Resistant canons can be left fully aware of their condition but unable to control their own bodies.