User blog comment:B214/Volume 23 discussion blog/@comment-31137559-20170413122356/@comment-30924344-20170413140113

No Diehauser does not. To understand something means to learn everything possible about what you are trying to understand. Diehauser may know one or two things, but he can't render the Evil Pieces useless because 1. The EP have so many secrets that have specific requirements or encounters to unlock them, so he can't just analyse them and 2. If Ajuka the smartest Devil doesn't know everything then neither will Diehauser who's intellect is inferior.

Also Diehauser can't render Issei's Penertrate useless and neither can Issei do the same. Worthlessness and Penetrate are the same ability; to bypass other abilities not of their own and so connection will just negatively cancel the other out. They just work different ways.