Set the Seekers against the Phantoms, the Survivors and the Hidden is the name of the fifth unique mission, offered by the buildings of the Mercators in the Desert Sector.
The mission will be offered after completing the mission before.
The Mercators need everybody in the Desert Sector to be at war with the Seekers. The easiest way to accomplish this task is that the player becomes a Seeker, at which point he will be able to kill others "on behalf of the clan" and do everything to interfere with them. Some time later, they will start hating not only him, but the entire Seekers clan.
When the other clans engage into the war with the Seekers (relation towards them must be lower than -5.00; that can be checked on the network), the player can come back to one of the Mercators' buildings to get his 25000 energy crystals as reward.
Accomplishing this mission unlocks the next unique mission.