That was quite the scene! I personally didn’t find it that disturbing since it was just so absurd… He’s dressed like Johhnie Walker, cutting cats’ heads off, eating their still beating hearts all while whistling hi ho. Kind of refuge in audacity 
I don’t think it’s meant to all come together perfectly… I wonder if that wouldn’t even kind of defeat the purpose of the increasing surrealism.
EDIT: Found this quote from Murakami
Kafka on the Shore contains several riddles, but there aren’t any solutions provided. Instead several of these riddles combine, and through their interaction the possibility of a solution takes shape. And the form this solution takes will be different for each reader. To put it another way, the riddles function as part of the solution. It’s hard to explain, but that’s the kind of novel I set out to write.
I thought that was maaaybe the same enitity as Johnnie Walker? And also the one having its face torn up by the boy called crow in the earlier chapter? All the while laughing like a maniac saying he couldn’t be killed because he had no physical form.
I got the sense that all of this was in order to stop that thing from getting into the entrance or something… But in that case, if the entrance was closed with the thing on the outside why not let it back in? Why open it? Or maybe I’m way off track here 