The more I think about it, the more I feel that there might be two conflicting theme going on here. Like Ten and Wade said, if you are going to make a story about Monsters of human legends, make them actual monsters and not Ancient Aliens or Outsiders. Otherwise it's just clunks up the narrative. The fear of something that comes from outside and the fear of something that comes from within are two very different stories. And while the latter is kind of infringing on Werewolf territory, well that's just the problem when you make a game about being Primordial Monsters when you already have a game like Werewolf.
That's doable.
Ages ago, in the time before time, you Were. You were an existence unto yourself, who needed no justification. You were a king, you were a god.
When these tiny hairless apes evolved, you thought little of them. They were beneath your notice. Sometimes one would get in your way, unfortunately for them. Sometimes they gave you tribute. You really didn't care. They were awed by you, as they should have been. And they were terrified by you, as they should have been. But you really didn't bother paying attention to them.
And then one day, you found yourself tied down ropes and chains as bronze and iron spears pierced your hide. For humans always seek to tame the awesome and destroy the terrifying.
Somehow you were able to claw your way back, drawn by their stories and their lingering fears.
I'd get rid of the feeding mechanics, personally. Beasts shouldn't feed on fear, it should not be a good thing for them. You're basically a dragon whose awesome power is straining against the limits of your mortal flesh and might at any moment explode out of your fragile human shell. And everyone around you can sense it. It causes awe, it causes fear, and you can't turn it off. It's not the same as a Promethian's Disquiet, though. It doesn't cause torches and pitchfork insanity. It's more of a "just look at that guy," thing. You're a bigshot. Powerful, dangerous. People might be relucant to deal with you, they might cross the street to avoid you, or they might just be overly eager to help you.
Beast really needs 3 things.
1) The ability to stand fully on its own.
2)An actual central theme.
3)The ability to become a motherfucking dragon in the real world, as a basic power. Because that's basically what you bought the game about being a motherfucking dragon for. If you can't flip out and get your Godzilla on, there is no point.