User blog comment:Jopjopjop/Volume 18 Spoilers/@comment-3965848-20150515062944/@comment-208.169.87.118-20150515201041

Penetrate is used to make your attacks to hit but, Issei used it on his eyes and was able to see through clothes showing us that you just have to think outside the box, Chichiryuushintei.

Reflect isn't Issei's power naturally so maybe his level of skill will never be the same as a White Dragon Emperor or, maybe it is because he has to use it through the WF that he can't do it or, maybe both, Striker.