Intelligent Items And Immunity Effects

[Kerian Valentine]

Our party recently received a very powerful intelligent item with an Ego Score of "really freaking high". It came up that we had several methods to make ourselves immune to Charm effects, and that the Paladin will eventually be immune to Compulsion effects.

Does immunity to Charm or Compulsion negate the ability of an Intelligent Item to possess its wielder? Alternatively, if not, what immunity would be necessary? Immunity [Mind-Affecting]?

[Valdast]

As far as RAW goes, there's no way to block the possession via Immunity. It's not any sort of Compulsion or Charm, it just happens via a single Will saving throw.