User blog comment:B214/Volume 23 discussion blog/@comment-31137559-20170414184220/@comment-10330822-20170417024535

But wouldn't that be an ultimate spear versus an ultimate shield concept? Penetrate is an ability, whether it is defensive breaking or not, meaning it should logically be able to be negated, and Penetrate should be able to penetrate through all defensive moves, like Worthlessness.

In short, I can see them cancelling each other out, but that still leaves the proposal that it shouldn't help Issei penetrate Diehauser's demonic energy, because Diehauser's ability to blocking Penetrate. Nor, logically, should it stop Diehauser from negating Issei's other moves.

Ultimately, I can see Issei needing total strength to overpower Diehauser, abilities may not be enough.