Thesaurize: The Completionist Chronicles, Book 10 (Unabridged‪)‬

Life smashing your walls? Build them taller. Then put auto-turrets on them.

Joe the Ritualist and the town of Novusheim have survived their first major battle, at the cost of leaving most of the settlement a smoking crater. Only most of it. The core of the town survived, and permanent casualties were low. Now that the survivors have a better understanding of what to expect, they go on a reconstruction spree...but why stop there? Every inch of their upgraded defenses will be more potent, durable, and deadlier than ever before. 

Even as Joe is kneeling knee-deep in blueprints, an urgent message arrives; sending the Ritualist venturing across the frozen wastelands of Jotunheim. With the safety of his own town mostly ensured for the moment, they can’t make him stay...but not a single person wants him to leave. Trusting the wrong person has been Joe’s downfall more than once. As the cherry on top, Grandmaster Havoc tasks Joe with obliterating any Elven settlement he comes across.

It's better to end threats early on, before they have a chance to stab you in the back.