We have threads on Xena, Warrior Princess, and there is some fan art of her and Gabrielle being crucified. Game of Thrones has some crucifixions. Photoshopping and manips of characters might fall into the fan art category.
In the end, a lot of this is probably in a gray area - there is no way to make a rule for everything without restricting things to the point we can't express ourselves at all. Probably using your best judgement is the best idea. In the end, if you aren't breaching copyright, not defaming someone, and your characters are all over 18, you are probably okay. This is all for use here only, after all. If you go public or commercial, the rules are different and a lot more strict.
Well said, Jolly.