First of all, there are lots of people who have dark thought, enjoy aggressive or violent entertainment..
Second, VR is a place of endless possibilities.. where you can fantasize about basically anything.
Will VR be a good option to satisfy the needs of some individuals without harming others?
HIT ME!

First of all, yes, it could help people to enjoy or practice whatever beliefs or violent entertainment one might have. It's a virtual space, so, definitely not harming anyone.
Second, since these group of people may have their own ideas or philosophies, a separate virtual space will be needed, or rather they can create their own virtual space to do whatever they want. I believe people who share the same ideas will group together and have fun in their virtual space without literally harming anyone or themselves.