Call of Duty: Black Ops 3 Zombies (DLC #3 Descent) - Fire Mission Trophy / Achievement Guide - In Gorod Krovi, kill 8 zombies with a single Dragon Strike. [Bronze]

First you need to do these two things:

RIDE A DRAGON TO PACK-A-PUNCH AREA
SURVIVE A LOCKDOWN EVENT (IN PACK-A-PUNCH AREA)

After completing the lockdown event you can pick up the "Dragon Strike Controller" in the Pack-a-Punch room. Now go downstairs and exit this area via the sewers. You can only use the Dragon Strike outside! Run in big circles to get enough zombies. Then press D-Pad Right to place the Dragon Strike. The zombies will automatically run into it and stay in place (just like monkey bombs). A dragon will come and kill the zombies.
Because the zombies are automatically attracted by this weapon it's quite easy to kill 8 at once. The only hard part is getting this item.

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