Ok the ghoul is for sure a bug. I finally got the bloodstone from the mine cave and when me and helena was going to the cave to see the Monolith thingy, the ghoul appeared in not even a second (I mean instantly, like straight up jumping on my face) , trying to kill me. Unfortunately for him, the power of cutscene is stronger than him. Haha!
Edit: Welp, maybe the power of cutscene isn't enough to deal with him... I kinda get the bloodstone at night so I can't really mine the Monolith. Tried to go out and guess what? the ghoul is back. Can't escape him now. For now i can just give the bloodstone at day so i can mine the Monolith, but after that? Can't get out cuz i'll just get insta killed by the ghoul. So yeah, now I'm officially stuck for good.