Racial Heritage and Fiendish Heritage

[CecilAlucardX]

Here's an odd question: What happens when a Level 1 human takes both Racial Heritage: Tiefling, and then Fiendish Heritage? Does his ability modifier change from +2 to any to say, +2 Dex, +2 Wis, -2 Int for Asura spawn? Does he get the variant roll? Does he lose his skill bonus?

[Nefreet]

You can only choose other Humanoid races with Racial Heritage (Tieflings are Native Outsiders).