Defeat Siegecrafter Blackfuse without destroying each of the following weapons in Siege of Orgrimmar on Normal difficulty or higher.
This achievement is exactly how it sounds, and can be completed over multiple kills. The quickest way to do it requires just two kills: First, do one kill where the conveyor belt players kill nothing but Missiles — which is a common strategy — netting you credit for Magnets, Lasers, and Mines. On the next kill, keep the Missiles alive by instead killing either the Mines or Lasers.
However, if you are completing this achievement on Flex mode and have good gear, you can instead opt to earn the achievement in ONE kill by ignoring the conveyor belt entirely.