Will Karl ever bottom?

Since this is something people suggested or even asked, I'll give a short answer first: yes, Karl will definitely bottom.

The long answer is a bit more complicated. Although I see him taking this step, it won't be until much later, when he's more grownup. How he'll get there will also be a complicated story. 

And I'm sure it will happen in the sequel to Prison Island, which will be called In It For Life and will be published everywhere just like Prison Island.