Theory: What if Miura is kill? Think about it - when was the last picture of Miura taken? If we saw a picture of some random Japanese guy and were told it was Miura, would we even know if it wasn't? 

People always talk about the change of tone in Berserk, and nowadays with the digital art it's like a completely different manga...

So what if Miura died in the early 2000's, and he's been replaced by his assistants that like harem manga and One Piece?

It explains everything