After Darkseid's defeat thousands of years ago, one of the Mother Boxes was entrusted to the Atlanteans for safekeeping. The Atlanteans then placed the Mother Box at their stronghold. The Atlantean Guards were established to protect the Mother Box.
Steppenwolf came for the box, following its scent which the Parademons were able to track. They were unable to pinpoint the location, but captured the perimeter guards for further interrogation. Using his mind probe device on one of the guards, Steppenwolf was able to extract the location of the stronghold, where he would find the Mother Box, and so he set out to attack it.
During Steppenwolf's attack, the Atlantean Guards, commanded by Mera, defended the stronghold. They attacked Steppenwolf with their rifles, but most of the guards were slaughtered by Steppenwolf, who managed to easily steal the Mother Box even after Arthur Curry's intervention.
- Armor: The guards wore golden armor while stationed at the redoubt.
- Hydro-pulse rifles: Most of the guards carried powerful hydro pulse rifles.
- Tridents: The guards stationed at the stronghold's entrance carried tridents very similar to Atlanna's trident.
- At least two Atlantean Guards are capable of breathing air, one of whom was a perimeter guard stationed far outside the stronghold's walls. As confirmed by Aquaman, this means they are highborn, so it's possible the entire unit was comprised of highborn Atlanteans.