:P I don't have time to read very far, but...
>>The first page
^ No. This is your first page. This is the title of your first page. Your first opportunity to grab your reader's attention. "Generic" / "Default" is a big no-no if you want people to sit up and pay attention.
>>An ominous sound echoes through an empty, forgotten dark hallway.
... Ok. What was it?
>> The black, shiny marble walls are stained with memories of terrible. twisted things.
If you want my opinion of writing, I'm going to encourage poetic description. That, characters, and angst are what I do best. "Black" is explanatory, but common-place. "Shiny" is also common-place. Writing is art, and while there are moments when simplicity and bluntness is best, descriptions are a chance to fill your world with color and emotion. Your choice of words is everything. (Also, I'm assuming you meant for that period to be a comma, otherwise we need to talk punctuation and capitalization.)
>>The guards stand behind a very old gated wall.
Actually, we need to talk punctuation regardless. If you're listing things / stating multiple attributes, you use commas. "She was a fair, sweet, gentle-hearted lass." "He was a cold-hearted, iron-fisted, evil bastard." "It was a very old, gated wall."
>>Behind the wall comes the hellish nightmares that scar this hallway.
^ Awkward. "Comes" does not go with "nightmares." Either "Come the nightmares" or "comes with nightmare." The sentence is a bit awkward regardless. "From behind the wall, in seeps the hellish nightmare that scars this godless hallway." (Yes, I embellished.)
>>The source of darkness comes from this one room.
The source isn't coming from the room, (as your sentence imples) the darkness is, so remember to make your wording clear.
>>But nothing ever leaves.
^ Except the darkness, you mean? And this could've been part of the previous sentence.
>Except for him. The creature. It. A thing of darkness, just a figment of Death himself.
And him, I guess. Also, I normally despise sentence fragments, but I do accept them for emphasis and style--just don't overdo it or it loses impact, looks unpolished, and tends to annoy.
>>Torches with fire trying to desperately vacate the room.
As... opposed to torches with water? xD Isn't this redundant? (And you may want to clarify that they're trying to vacate the room of darkness specifically, because otherwise, they just sound like rude landlords or like they're trying to burn the crap out of its one mortal inhabitant to make him leave.)
>>A man, strapped to a chair is screaming bloody murder.
The comma here doesn't really serve a purpose. You could say it's a pause, but it's a weird pause.
>>Wires and devices prob at him, dealing the most damage any Human being has felt.
Probe has an e on the end, human needs no capitalization.
>>The dark figure stands over the decaying corpse, waiting for the man to finally die.
He's waiting for a corpse, defined as someone or something who is already dead, to die?
>>But he enjoys it, the sick smell of death and despair.
The "but" is not needed. There is no reason to believe this statement contradicts / acts in opposition to the previous one. (Like in the usage "I don't normally go to concerts, but my favorite musician is playing." I don't believe this is out of the ordinary for this figure.)
>>The creature is known as the Reaper, because of his uncanny ability to ride time itself without a trace.
... Wouldn't it make more sense for him to be called a reaper for a tendency of collecting souls or something, rather than time travel or disappearing? Because, disappearing without a trace would bring to mind a name like "phantom" or "ninja," and time travel would suggest a name like ... Doc Brown or Chicken. :P (BTTF joke.)
>> "Excellent...Leave!"
That really should be "Excellent ... leave!"
And that's all for now. I find the premise intriguing at least, I like Grim Reaper style characters / angels of death.
