User blog comment:B214/Volume 23 discussion blog/@comment-31137559-20170414184220/@comment-30924344-20170417023733

Penetrate: Bypasses defensive abilities. Worthlessness is a defensive ability. Issei is the only known one the Belial's clan ability does not effect. Even if Diehauser understands how Penetrate works, its pointless because the effects of both abilities cancel each other out, as they are both defensive abilities that negate defensive abilities.