User blog comment:B214/Question and Answers 4/@comment-4547267-20141128000402/@comment-24502975-20141128160757

You've read up to volume 17, haven't you? Isn't it obvious? He's not unlocking Penetrate, Reflect, and Longinus Smasher due to lust. He's now at a level where he can grow stronger without relying on lust/oppai-related power-ups.