Decimated

The King of the self built and highly successful Fort Coppertop, Julian had it all. Except his best friend back. But in trying to bring him back, he spawns the Wither in his own kingdom. They escape to the Nether, only to be trapped there. Now, they must learn to survive, lest they be Decimated themselves. And to top it off, how is he supposed to tell them that he was the cause?