Lately I've been remembering something in bits and fragments, and for me that means I have to find the source material and read it through again. This came from one of the many, many writing sources I've read over the years, and honestly it could be anything. This is just a shot in the dark, but let me know if it strikes a chord with anyone else.

The text was talking about the technique of pacing, how to make a passage seem to go by faster or slower. When actions are summarized, it says, the pace of the story moves more quickly. An entire afternoon may go by in a few sentences. When things are told in detail, the story moves more slowly. A fight scene may take most of a chapter.

I've checked Jim's blog and it's not the source I'm looking for. Does this sound like something you've read? Have you read something else that seems to be communicating the same idea?

These are just the things I jotted down as I read:

There's a limit to how many modifiers a noun can have before the audience loses track. Alone, the adjectives bright or spinning would be fine. The reader could use them to paint a picture without much thought. Multi-hued is a bit awkward. The reader has to stop to think about what it means before they understand what you're telling them. Ditto for a few other places in the passage.

You're vacillating between present and past tense. The narrative should be present, I do this, or past, I did this. It should not be both.

"I regain the composure I don't ever remember having and slow my quick breathing." Too many ideas in here. The character is composing himself. The character is not normally composed. It's taken him a few minutes to wake up, and he's still groggy. Why is his respiration up, that he needs to slow his quick breathing?

"I open my eyes just enough to see that the sky was dark blue, and deduced that the sun was just rising." Again, past/present tense agreement. This is a good place to show and not tell. Give me birds chirping. Show me rays of sunlight just barely touching the treetops. Let the sunrise be the underlying cause, and the sensory information be captivating. I'll figure out that the sun is rising without ever thinking about it.

Dangerous animals live in the forest. Is he a park ranger, that he knows to be afraid? Or is he a city dweller with an irrational fear? Paw prints or scratch marks on a tree trunk would be an undeniable sign that danger lurks.

Quickly. In most cases, an adverb can be deleted and the prose is better for it. This one feels overused here.

Pulsating blue strips that are one-fourth of a centimeter in width. I can't eyeball a 1/4 centimeter. I have to stop reading to think about it.

Ever-encroaching trees. Encroachment carries a connotation of competition. Saruman's orcs encroach upon the lands of the kingdom of Rohan. Trees don't encroach upon humans, they're part of the environment. They could encroach upon a wheat field, or a brush line, but not upon a human.

Without moving my torso. Here the action of the arm stops to tell the reader that in another place, nothing is happening.

Nor did I know the necessity for the replacement. I had to go back to read this line a couple of times before I knew what it meant. The reader is kicked out of the story when this happens.

You should probably rethink the names "white necromancy" and "black necromancy".  It's way too close to saying "good wizards" and "bad wizards", whether or not that's where you're going with the story.

Besides that, I don't see any problems with your magic system itself. Just remember that if magic is being used to solve narrative obstacles, your readers have to understand the nuts and bolts of it, so they can see the solution coming.

It might also help you to find a writing group, online or in person. They can help you with problems of grammar and diction and the like.