Still needs a lot of work. Unnecessary adverbs, circuitous descriptions, and the rest are still pretty rampant. Let's look at your first paragraph, and what I'd do to it.
Your version, all 164 words of it. Let's cut this thing apart, sentence by sentence.
"Dusk had settled upon the vast expanse of the ancient Forest of Valshyr."
"Dusk settled upon the Forest of Valshyr."
Nobody cares that it's vast and/or ancient. Unless it comes up later when people are actually *talking* about said forest, you can cut that out.
"After four days of eternal sunlight, both suns mercifully saw fit to slumber beyond the horizon."
"After four days, both suns fell below the horizon."
It's not eternal if it only lasts four days, just saying. Also... how does one measure a day in a place without a sunset or sunrise? I'd just drop the "dual suns" thing, myself. Oh, and if the word ends in 'ly', you can (probably) delete it. And there's no reason what so ever to personify the sun unless you're doing a specific type of story that you aren't doing.
"The ample, eager moon now had its turn in the spotlight."
"The full moon now had its turn in the spotlight."
There is no reason at all to describe the moon to such detail, let alone with sensual words like 'ample' and 'eager'. That belongs in romance novels. You don't appear to be writing a romance novel.
"The magnificent shape crested the hills that flanked the forest on all sides; full and round, it imposed its will upon the rest of the still evening sky."
"It rose over the hills that flanked the forest on all sides."
We know it's a moon, no need to call it a "magnificent shape", and since we were just talking about it in the prior sentence, the word "it" will suffice. We also know it's evening, no need to mention that. And it's an inanimate celestial body, it doesn't have a will to impose.
"Ordinarily, the insects of the forest would come out to worship this newcomer to the sky; to celebrate the death of one day with the birth of another."
There is no reason to keep this sentence at all. We can convey its ideas in the next.
"Yet, the evening air would be quiet this night, as it had been every night for as long as anyone can remember."
"The silence of the grave dominated the forest, as it had for as long as anyone can remember."
THIS is a situation where a personification word applies- something foreign, alien, in a forest without life. Conveyed in as few words as necessary.
These two sentences can be folded with the last into something like:
"There was no breeze, no rustle of leaves, no song of insects other nocturnal animals."
And of specific note... try not to repeat the same word (with exception to certain 'invisible' words like 'a' or 'the') more than once in a paragraph. Let alone one like 'ordinary' which you can often avoid using at all.
Now, here's how I'd put together your first paragraph after cutting it apart:
"Dusk settled upon the Forest of Valshyr. After four days both suns fell below the horizon, making way as the full moon rose over the hills that flanked the forest on all sides to take its turn in the spotlight over the silence below. There was no breeze, no rustle of leaves, no song of insects other nocturnal animals. Death ruled here, as it had for as long as anyone can remember."
Having cut the sentences to shreds, I was then forced to modify them further so they fit together again. I merged a few sentences, repositioned some of the prose, and whittled your 164 words by 55% to a much more readable 72. I could slim it further, but doing so would make it so different that it would no longer resemble yours in the first place. And that's not the goal here.
Now... I know, I personified 'death' after telling you to stop personifying the sun and moon (and will now tell you not to personify the valley at all). The difference being that, at least in this case, 'death' is an active force that is doing something specific and dangerous.
You could personify the sun in a situation like, say, the middle of a desert where words like "oppressive, lethal heat" would make sense. There, the sun is important. Here, the sun is not.