The light of the morning stirred his consciousness and he groaned at the exhaustion that still lingered. He opened his eyes and found himself in unfamiliar surroundings. It was not an uncommon occurrence. Light from a window overhead flooded his face. He lifted a tired hand and massaged his eyes, willing the heaviness to leave. His hair was slick with sweat and whatever else may have been keeping the shed floor moist. He ran his fingers back through it, pulling it out of his face and removing bits of dirt and straw. As he turned his head to the side he saw that he was in a small shed. He had slept on the straw covered ground and various tools and barrels surrounded him.

He sat up, a bit too quickly, and felt a surge of nausea as his vision came into focus. A pang of fear struck his stomach and then just as quickly receded, taking the nausea with it. Most of it anyway. A dark, recognizable figure sat hunched in the corner of the shed. It turned its head to the side as it looked at him, long black hair falling into its face.
“You should thank me Darren.” The voice was slow, cool, like a drip of water into a cavern pool.
“You were almost destroyed.”
Darren wiped his tired face and pushed himself up to lean against the rough wood of the shed.
“Ilomen” Darren grunted and cleared his throat. “What happened?”

To a lesser extent, the same rule should hold the moment a POV character recognizes someone...let the name out of the bag.

Most the other things I could mention are just nits. But since you're looking for feedback on these thirteen, I'll oblige

"The light of the morning...Light from a window overhead..." is a bit of a repetition, and the placement of the window "overhead" is inappropriate. For one thing, an overhead window in a shed doesn't make much sense. For another, morning light from an overhead window wouldn't flood his face. A window (or some kind of opening) on the opposite wall makes more sense.

"He opened his eyes and found himself in unfamiliar surroundings. It was not an uncommon occurrence." Remember to notice the unusual, not the expected. Perhaps he's more used to waking up outside? Or inside something other than a shed? Say that, and we get all the other information by implication.

"As he turned his head to the side he saw that he was in a small shed. He had slept on the straw covered ground and various tools and barrels surrounded him." This needs to be tightened up a bit. First off, we already know he was in a shed, on the floor. The only new information is the othe contents of the shed.

Have you ever "felt a surge of nausea as your vision came into focus?" And the line about a pang of fear coming and then taking off with the nausea is simply puzzling.

"A dark, recognizable figure sat hunched in the corner of the shed. Ilomen." As before, don't tell us the POV character recognizes something and then fail to tell us what it is. That breaks POV. If you must do that, write in narrative voice rather than POV. But remember that one reason narrative voice is less popular than POV is because readers hate this sort of trick, particularly when you have no reason to pull it.

"Darren wiped his tired face again and..." yeah, before he rubbed his eyes (with slimy hands but oh well) and raked his hair. Still, when you show a character doing essentially the same thing again, it can sound repetitive unless you clarify that it is indeed another instance.

The phrase "pushed himself up to lean against the" isn't very clear. For one thing before he was surrounded by tools and barrels...but oh well. For another, it isn't clear whether he pushed himself to his feet, or whether he's just sitting up again after his little nausea bout.

"Darren grunted and cleared his throat." He should either do this before talking, or after discovering that his throat needs to be cleared. I suspect you want the latter effect.

Overall, while the prose could use some more polish, it is intelligible and correct. Think about POV as you write, what the POV character notices, what he sees. Visualize so you know what you're describing. I know you've put yourself in this character's head, put yourself in his physical place as well. The affect of this segment feels quite coherent, very effective. But some of the descriptions of physical things don't make much sense.

Yeah, you mentioned being aware of that. Like I said, just visualize things as they would look from the physical perspective of your character. You might even try a few instances of acting stuff out, find a shed and sleep out there