Dude.. you've been bamboozled.
The worst dofantasy can do is sue you. In europe and north america, you won't go to jail for 20-40 usd per comic which IMHO is WAY TOO MUCH for those comics and at the same time, far too cheap to sue over to get their money. And in most courts, when they find out what content Dofantasy specializes in, their prospects get MUCH WORSE. When you factor in that they are set up like a seedy, overcharging publishing house for torture porn, your chances actually improve. Who wants to defend an overpriced clearinghouse for torture, necrophila, and guro porn? NOBODY with half a brain.
So, their "lawyerly" letter to you is stand debt collector bullshit. I dare Dofantasy to show evidence that anyone has ever gone to jail over this. Or that they've even won any lawsuits. I think their standard way is to to constant DMCA requests and attempt to scare everyone into submission just to make a few more bucks.
Shame on you, Dofantasy. Your attitude is much worse than your content.
BTW...A copyright lawyer friend says if his firm was asked to represent Dofantasy, they would say NO.