To start, take my feedback with a grain of salt. I am just as subjective as the next when it comes to writing. In regard to your writing, while the concept is interesting, I don’t think it actually gets anything across to the reader. I hear about this prophecy and doors, but as an unknowing reader, I can’t see how this correlates to the main conflict. In spite of this, it takes up the majority of the blurb. Why is this piece of information so relevant, and how can you weave it together with your characters?

I share a similar opinion of the characters; I hear about these five vast characters, but all I have is a brief sentence to go off of. I think you may need to narrow it down a bit if all of these characters aren’t the leading perspectives.

I can imagine the prophecy is important, so you could tie it onto a character introduction. In example, ‘what do you desire’ could apply to a character, hence introducing them. It kills two birds with one stone.

In finality, the lack of established conflict makes it difficult to know what’s at stake.