Having brought an EMP device into the Batcave: Outer Caverns with Robin, Batwoman and Huntress to release Brother Eye's hold on the security terminal, it is revealed that he, along with the other Bat Family members, have been secretly infected with the OMAC virus and are activated by Brother Eye in an attempt to prevent the player party from progressing further.
- Brother Eye and Brainiac have taken over the Batcave's mainframe and, along with it, the substantial automated defense and security forces. Both heroes and villains battle against Earth's real enemy in this 8-player raid.
Each Bat Family member has their own styles and behaviour. Blocking their normal weapon combos will stun them (not unlike a PvP fights) and they will sometimes come to each others' aid, briefly shielding them from damage.
Once their HP is low enough, they will get enraged and will do more damage for the remainder of the fight. When one of the four is defeated, they will become inactive, warp to one corner and begin draining the EMP. After about 20 seconds, indicated by a progress bar behind them, they will revive with 20% HP and re-join the fight. To win, all four must be inactive at the same time and one player must quickly trigger the EMP in the center of the arena or they will get back up again.
A good strategy is to focus entirely on Batwoman - she deals the most damage and has a tendency to chase the healers. Once she is brought down, continue damaging the other three, re-focusing Batwoman when she revives. Tanks should focus on reducing incoming damage via well-timed blocks.
To properly get a time window to trigger the EMP, the tanks should gather the four in one spot after they have low hp (about 15-20%) and the raid should bombard them with AE damage to ensure they go down at roughly the same time. If it fails, wait for the incapacitated ones to revive and try again, otherwise they might get stuck in a loop of re-defeating one just as another revives.