Thanks for considering :)

They can be immune to magic, if you wanted to go down that route.

You can include their weakness/strengths in the story-line as it unfolds in the Ic. It doesn't necessarily have to be noted in their character sheet unless you want to add in that section by yourself. 

Same goes for the healing factor. But I would include that under Immortality-they can't be killed easily, hence the regenerative healing if they are harmed.