What utter rubbish. 'Atone for your crimes'? I've never met a monster that didn't die upon being atomized. Finding the location of the summoning, I expect, will be the hardest part. After that it's only a matter of how much force we can bring to bear.
And if the summoning completes... well. We have a veritable army and I've seen bigger threats than some overgrown lizard laid to waste by a party of less than ten. The right people in the right place can make all the difference.