They engage PrideCrusher alone. Seriously, I was once in a group of five remaining soldiers left to fight one Mr. PrideCrusher. Thinking I was the last warrior I tried alone for 30 seconds, losing two shields in the process. When a friendly archer showed up I said "shoot PrideCrusher!" but he pulled out a claymore and charged. After he died I ran and got the three other remaining guys and engaged PrideCrusher again. While I rushed in with new shield raised one other guy came with, the other two skulking in the background. My companion and I died, as did one of the remaining two warriors, before the last one did a lucky two-handed swing which PrideCrusher blocked the wrong way.