Wow! That was pretty cool! Love the descriptions about how the shield didn't do much. Hehe.
Some minor, minor stylistic criticism though... In this line,
The old man had stepped outside to see why the cows were bawling and been picked up and devoured in a moment. That confused me a bit from the way it was worded, thought we were still talking about the
cows being picked up and devoured.
But like I said, minor stuff. :)