Chapter 2:
The Shadow of Ultimate Darkness
Darkhenus
Darkness reigned supreme on the damned castle that Darkhenus had erected for himself on the North.
(space needed)
Those cursed wall
s breathed
(wrong word choice...I know what you're trying to say, but it's confusing if you used breathed) with the whispers of the human slaves who had died building such a horrific castle. Those human slaves were the pour souls who hadn’t got the chance to escape from the North before Darkhenus had arrived.
And now,
on in the most tortured chamber of that
demoniac demonic palace, Darkhenus stared at the flaming dark shadow that had appeared.
“So, what do you think of my palace, father?” Darkhenus asked, waving his hand on the direction of the walls
(walls or wall? If it's walls, then it's too vague, since most places have 4 walls).
The shadow seemed to look around, apparently
(?) admired, however Darkhenus knew that was no more than a mere act of courtesy.
His father wasn’t the type of man to appreciate architecture.
On the other hand, his father was
even hardly a man
at all.
Seeing that the shadow wasn’t going to answer, Darkhenus talked
(maybe you should use spoke again. “It is nothing when compared to the gigantic fortress that you reserve for yourself on the Mainland.”
“It seems you are plotting you schemes again, Darkhenus, my son
,” the mouthless shadow said
, “Despite your condition as the strongest of my sons, you were always the one who liked to conceive the plans for the battles. You brothers enjoyed more the heat of battle and the blood of the enemies.”
Darkhenus laughed, enjoying a private joke
. “And that’s why they are dead and I’m alive. A strong mind needs to be in an even stronger body, don’t you agree, my
(the 'my' seems unnecessary) father?”
The shadow crossed its immaterial arms; Darkhenus admired how
is Father was able to maintain a physical presence there by using only the shadows of the castle, while his father’s real body was in safe in the Mainland.
(Run-on sentence)
(space needed)
Even Darkhenus himself needed to use a dead body to do that.
“Where do you think that this path you walk will take you, Darkhenus?” the shadow grumbled.
(grumbled? it doesn't seem like the right word for this scenario)
“Where else, father?” Darkhenus answered, smiling with the smile
(smile is getting repetitive) of a madman
, “To the fiery pits of Hell, of course.”
“After all, I am a messenger of the most pure
(try using purest instead 
) Darkness while you
, my father, you are Darkness itself, are you not?”
(this line seems awkward)
“For me and for those who serve me there is only one possible end. Hell itself.”
“But first, I will make this whole Continent burn!”
The shadow’s eyes met his son’s. “What is Thelmus doing?”
“Thelmus is doing what he likes to do the most.”
(space needed)
“Kill
ing people.”