Deep Sea Corruption

Deep Sea Corruption is a weekly mission given by Loyalist Iona in Mera's Royal Hideout in the bottom level of the southern edge of Atlantis (Location). It is only available after you have completed Atlantis (Mission) up till the point Aqualad asks you to queue for Atlantis: The Silent School.

It requires you to defeat the giant Brine Hulk in the farm in southeastern Atlantis.