Hidden casters who cloak Shambling Berserkers in empowering darkness and launch anti-magic bolts from behind the undead.
Two city elves approach Carl, Princess Donut, and Mongo from opposite ends of the street while a dozen undead advance under supernatural darkness. One destroys Donut's magical Torch with a green anti-magic bolt.
The elves stay behind the Shambling Berserkers, maintaining the darkness that quadruples the monsters' strength. Carl kills both with explosives, instantly restoring daylight and reducing the surviving undead to fragile piles of parts.
The casters remain almost entirely concealed by their own magical darkness.
The elves control the ambush and provide the critical targets whose deaths collapse its magical advantage.