Speaking as one of the people who did the major rework of the CotBG last year… I can't say I terribly care for the first part. You have the format down pat (Even if it is a tad long), but there are a few things wrong:
- "Flesh" shouldn't be in all caps. Whenever "the LORD" is in all caps in the English Bible, it's a replacement for the name of God in Hebrew, written as YHWH, because you cannot say the name of the lord. By contrast, the name of Satan (which is what the Flesh essentially is), is just a proper noun.
- This draws waaay too heavily off of actual Greek myth. There's always been an implication that the Broken God is Hephaestus ("broken" in the sense that he is crippled), which I'm glad you picked up on, but outright referencing Mount Olympus and the Cabeiri feels less like re-imagining and more like taking a few Broken God things and viewing them through a Edith Hamilton-colored lens.
- I really don't like the fact that you literally made Cain of all people Hephaestus, and by extension, the Broken God's avatar. It conflicts with my headcanon twelve ways to Sunday. Also, other than saying "Cain is the Broken God", you don't appear to have changed anything about the concept, you just changed the backstory. Speaking from my own experience with the contest, this will fly as well as a tungsten balloon with holes in it.
- It's the Wanderer's Library. Yes I know this is a tad pedantic.
If you cut out the first two bits, I might like this; the Wanderer's Library bit is really interesting (I like the idea that the Flesh is another term for the sea people), but you really need to change the concept more than "He's the Broken God". It could be as something as simple as "Cain is a woman" or something as complex as "Cain is an attempt to meld the Flesh and the LORD/MEKHANE/WAN together."
Also, the fact that this is Cain opens up a bit of a plot hole; one of Cain's anomalies was that he can't be around plant matter (Genesis 4:12 "When you work the ground, it will no longer yield its crops for you. You will be a restless wanderer on the earth."), but is perfectly fine around meat and other forms of flesh (which is why he doesn't erode humans to dust). However, saying that Hephaestus "displaying disgust for the flesh" doesn't make much sense.
That's all I have to say.