War Hulk Ability

[Zorikune]

Alright, so I've been working on the War Hulk prestige class for my friend, but there's this one ability I'm trying to figure out. I need to know how to set the prestige class to where anyone who take a level in the war hulk to consider them having 0 ranks in intelligence, wisdom, and charisma-based checks, even if they have ranks in those skills, with the exception of intimidate as that skill functions normally. Let me know if anyone knows how. Thank you. =)