Answer:
At first, I am nothing. Add something to negate. Add again to oppose. Add again to find the time to draw. Add once more to find nobody at all.
What has a big mouth, yet never speaks?
Walk on the living, they don't even mumble. Walk on the dead, they mutter and grumble.
Mountains will crumble and temples will fall. And no man can survive its endless call.
I build up castles. I tear down mountains. I make some men blind. I help others to see.
What has to be broken before you can use it ?
Difficult
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?