Vanquish

When boosting, evading, or when exiting cover, AR Mode can be triggered manually by pushing . This will put you into slow motion and a timer will be activated. You have to kill three robots before the timer runs out! The AR Mode will cancel automatically when the action is complete, your AR Suit overheats, or when the is released.

To manually activate AR Mode:

• boosting: hold +
• evading: push + press + hold
• exiting cover: push + press + hold

The red robots seem to be easy kills, especially on casual difficulty and/or with a fully upgraded Assault Rifle/Heavy Machine Gun. Make sure the robots stand close to each other, this will make it so much easier. Try to go for headshots as well, it helps a lot! Once the AR Mode timer runs out of time, your ARS temperature gauge will indicate it's overheated, so go into cover for a moment of cooldown.

Alternately, here is a solution as suggested by Solty on casual difficulty; use the Lock-On Laser on a group of red robots hiding behind cover when you're in AR Mode.

Another method would be throwing one or two grenades () at red robots grouped together, and when it hits the ground, go into AR Mode. If the grenades explode and destroy at least 3 robots, the achievement is yours. If all this fails, try again on casual auto.