Somewhere along the line, I got the feeling that Crayak destroys because he's trying to make some kind of ultimate species. Kind of an extreme way of selective breeding.
But when I reread The Ellemist Chronicles, he doesn't say that. He just says he destroys because he can, or something like that.
So is he trying to fulfill some twisted purpose, or does he just like to see how many different ways he can destroy a planet?
Both of these options being wrong, of course, but I find it odd that anyone would kill something over and over just because they have the power.
Even Adolf Hilter had a reason for what he did.