It's a sad thing, the death of a loved one. On the evening of his mother's passing, a courier delivered a letter to Damion. It was his inheritance. As he read the letter, he was shocked to find that he had inherited his great grandfather's estate. An entire prussian castle, far out in the country. He struggled to understand why his mother had chosen for him..., which struggled through life when THEY were entitled to an entire castle. He suspended the thought.
A fairly good custom story.
The monster encounters were a bit crappy, suddenly spawning a monster right infront of you isn't very productive to the atmosphere or to the gameplay either. You should add Amnesia-like monster encounters, where you hear them spawn somewhere in your vicinity, then the player will likely be more nervous.
Puzzles were rather original, not entirely, but I liked the style.
You also managed to make the dungeon levels a bit more interesting looking with your special effects, that was a nice touch.
The length of it all is also a plus, I personally didn't expect it to last so long.
The subtle PewDiePie references didn't really bother me, since you didn't exactly throw them straight at the player's face, which is a good thing.
The story was, however, lacking seriously. I didn't find any notes, see any flashbacks or hear any dialogue. I didn't have any idea what I was there for, and what had happened.
Also, I suggest lowering the amount of messages you give to the player, especially when you put a lot of "RUN!"s in there. Those can be an atmosphere breaker. Just direct the messages as if it was the character thinking, more.
All in all, like I said, a fairly good custom story. 8/10, and if you're planning on making future custom stories, take note of the faults of this one and correct them.