OOC Immunity is the ability to completely resist a Mary Sue's influence.
It is not the same thing as OOC Resistance, which allows partial resistance.
Only a very few characters are immune to being pulled OOC by a Mary Sue or slashwraith. These are all omniscient, omnipotent deities. If you find them OOC, they are always character replacements, because the real characters are more powerful than any Mary Sue. Sues who wish to create OOC versions of them have character replacement as the only remaining option.
Immune characters encountered so far:
- Eru Ilúvatar
- Aslan, who is always Tashlan in disguise if OOC
- God of The Bible (who might be the same person as the preceding two, considering the authors' beliefs).
Note that characters who are deities or deity-like creatures (but not infinitely powerful deities) tend to be merely resistant, but not immune, to going OOC. For example, the Valar, members of the Greek pantheon, and Eldritch Abominations can all be OOC. These instances are best handled by the ESAS, who are best equipped to handle them.
Character-replaced deities are generally quite capable of getting out of their own plot holes, and tend to be more than a little annoyed at the Suvian culprit. However, they will not do the PPC agents' job for them; such beings tend to prefer to encourage self-sufficiency and freedom. In some instances, they have been known to help PPC agents dealing with a character replacement or a very powerful Mary Sue, but this usually happens when the PPC agents' mission would have been utterly impossible without their help. Character replacements for omnipotent deities are not omnipotent themselves, but they do tend to be extremely powerful.