Guro and other splatter content would have to pass Miller's and not harm the site to be allowed. Since it isn't specifically illegal or obscene by virtue it isn't against the rules by default. The real litmus test for any adult content is 'Does it turn more people off than them turn on'. If uploaded content has the potential to drive members away then it would most likely not be allowed. In other words, don't post things that would get Max Hardcore arrested.
There is indeed case law where violent rape and murder in pornography was deemed obscene and thus illegal, but the instance involved human actors. To the best of my knowledge there isn't case law regulating those types of depictions in animated art or CGI genres. Without cause I can't recommend that Doublezero ban something simply because I don't like it personally. Necrophilia is illegal, but not CGI depictions of it.