User blog comment:B214/Talk About What You Want! 3/@comment-24098614-20150306011349/@comment-23853100-20150306034034

What further explanation do you need? It's already mentioned that the ability to negate clan abilities is exclusive to the Belial clan not just Diehauser. Asking any more explanation is like asking to explain how the Bael can use the POD, why the Phenex has immortality and explain how the Gremory has red hair. It's something they are born with.