Let's say that you're sacred text is perfectly moral, and all of the prophecies have actually come true in a completely unambiguous matter.
Given that hypothetical, why should anyone believe that a god is responsible, let alone the concept of God particular to your sacred texts?
What is a manticore? There is a series of comics (graphic novels) called The Books of Magic which reimagine the manticore, and I recommend reading them. In our own mythology the manticore is a creature which eats men, but in The Books of Magic it is a creature which destroys magic and magical...