I've already finished the normal mode. and now after I played nightmare mode, I've stuck in the third night (the calamity)I've beat 4 headless priest also himuro master. then, when I go to the moon well (beside cherry atrium) after I pushed the 4 button on the one big pillars, nothing happen!? all I know, when I played in the normal mode, I saw a blood coming out from that one pilars (in the front of me) and I must beat himuro once again. but why? maybe because this is a nightmare mode???

Okay, so you beat the four priests and pressed the four buttons, right? If the blood appeared, then you need to follow it and face the Himuro master for his seal. If I'm right about this, then you should be able to get into the Moon Well.

The truth is that I've only watched someone play this part on a youtube video. I'm pretty sure that I'm right, though.