A MLP: FiM crossover with Okami

It's been one month since the brave Amaterasu defeated Yami and regained her true form. But when Yami appears and opened a portal to an unknown place, two worlds collide and it's up to the Elements of Harmony and Amaterasu to stop the destruction of both worlds.

(This is my first fan-fiction ever so some friendly constructive criticism would be very helpful and I would be glad to receive more tips on improving my writing!)