One of the killers is stabbed to death with dozens of weapons in a scene that is both gratuitously over-the-top and gratuitously gory. The other man is hanged by his own grappling hook while trying to escape from the haunted house.
These two scenes, along with the bit where the possessed man vomits on Tripitaka (the most direct visual lift from The Exorcist), would be my evidence this week for why this episode was not considered suitable for the original TV run.
The exorcism angle is oddly suited to the format of Monkey, with Tripitaka taking the role of exorcist and Monkey guarding him from the demon's attempts to kill him. It is a change from the usual dynamic and helps make the episode dramatically interesting by varying the usual formula.
Pigsy and Sandy's main role in the story is to get captured by the killers early on, once again demonstrating how comically useless they are. In fact Pigsy is so useless he gets captured off-screen, and the first we see of him is when Sandy is thrown in a cell with him.