How do you protect yourself from someone that somehow rolled a 30 for charisma and also has no scruples? Calling people idiots when they've fallen under the spe

How do you protect yourself from someone that somehow rolled a 30 for charisma and also has no scruples? Calling people idiots when they've fallen under the spell of such a person isn't helpful. What would be helpful is this: suggest ways to adjust the system so that cults of personality can't gain traction when the stakes are high.