I'm going to be honest: There's a lot of odd wording and SPaG errors, so many that I'm tempted to ask you to revise it a lot more before I crit. I definitely can't do a line-by-line of this right now, but I see several repeated mistakes that I think you can focus on to greatly improve this:
You start lots of sentences with "And" or other conjunctions. Technically you should never do this. Some of these work fine stylistically ("And so people passed down…"), some can be fixed by either combining sentences or just removing the conjunctions (And if you have a rich imagination…), and some you may need to just rewrite the sentence.
There's a LOT of inconsistency with the capitalization. "gods" vs "The first generation of the Gods" vs "the First Age of the Gods". "Divine beasts" vs "Divine Beasts". Make sure that you capitalize consistently, and only break consistency with a reason.
Most of this is in "myth language", ie like in the Bible or a retelling of Greek mythology of something. Occasionally, though, you slip into informal modern language/tone, like toward the end when you say:
Fortunately, a few humans still survived, but it was also unfortunate that they had forgotten all knowledge of powerful technology and magic, leaving only a few who still remembered the teach about magic of the Divine beasts.
Keep an eye out for that, because it happens a couple of times, and it break the immersion when it does.
PARAGRAPHS, FOR THE LOVE OF ALL THINGS HOLY. Your longest paragraph is just 3 sentences, and most were only 1 or 2. There are times where putting something on it's own line is fine (like, "And from above, Demiurge smiled."), but most of these sections would look much better as 1-2 paragraphs instead of 5-15 individual sentences.
I really love the myth-making, I love the references, and I absolutely want this to succeed when it's posted! Please give it a revision or two and get back to me! I had a lot of fun reading!
A few specific things I noticed while reading:
He-who-is-flesh
Isn't Yaldobah a She? I could be misremembering. (Then again, who am I to assign a gender to the gods?)
But according to the few remaining clues, it appears to be overlapping gears, with flowing from each gear are streams of water that can turn organic flesh into metal.
His Broken Heart? A bit on-the-nose, but love the reference!
But Yzakad failed to exploit that power, which then led to the birth of the "Destroyer", and from that, the Great Cataclysm began.
I'm sure this is a reference that I'm not getting.
Great Cataclysm
BIONICLE REFERENCE!!!!
the blind idiot god Demiurge
His name is Azathoth, thank you very much. (Lovecraft reference?)
The Demiurge's blood poured down and created a giant flood…
And did this flood have an Ark?