At the end of each area, your team will need to take control of a Vanguard drone in order to demolish the Obelisks.
During this phase, players can take turns killing Gargoyles in order to attain the achievement. The Gargoyle is a new enemy type available in the
Invasion DLC, which looks like a large flying dragon. It can be found flying above, but will also land and run around occasionally.
Players will want to take control of the Vanguard, aim at a Gargoyle and use the attacks (both triggers) in order to hit it and kill it to gain the achievement. Once they get it, they can ascend to lose connections or purposely die for another player to get a turn. Gargoyles will continue to spawn as long as you don't demolish the Obelisks.