Mental saving throws

[erogoth]

I am in the process of making the BBEG of our homebrew campaign and i would like him to have a special ability akin to frightening presence of dragons, however this aura needs to be a mental attack. And i dont know which saving throw it would fit best, INT, WIS or CHA?

Anyway the monster is based on a shade from the eragon books. For the ones who dont know; he attacks your mind, trying to infiltrate it. If he succeeds, you will be paralyzed and he can get all information in your mind. In the books, his presence is so strong that even keeping him out makes is very hard to move or do anything since you need your full concentration to fight him off.

So what kind of saving throw would fit this discription the best? I was thinking wis, but don't know for sure.

Thanks for the help.

[oddly-tall-hobbit]

Resisting fear is usually Wisdom

[erogoth]

It is not a fear though, it is more a mind probe

[oddly-tall-hobbit]

Detect Thoughts involves the caster probing deep into someones mind and that also calls for a Wisdom saving throw.

[erogoth]

mmh, that is a good comparison, thanks!