Ancient Enemies Returned IX is a Weekly Seasonal Objective that repeats on a 10 week cycle when a Galactic Season is active.

To complete the Ancient Enemies Returned IX objective, you must kill both Warden Nymessa on Hoth and Overseer Qezzed on Coruscant.

Warden Nymessa

Warden Nymessa

Warden Nymessa spawns on Hoth at the Highmount Ridge, far South of Leth Outpost. She is found ontop of a hill near some Tauntauns and an ice lake.
X -1150 Y 1260

Warden Nymessa drops 1 Darkside Token when killed.

Strategy

Warden Nymessa has two mechanics that need to be avoided, she alternates using both of them although they can happen at the same time.

Every minute or so Warden Nymessa will apply a poison DOT to your character, you either need to cleanse it yourself, have a healer cleanse you or use a medpac to survive it.
Tank players should take priority when being cleansed, if you are a DPS player and the boss has a high amount of HP it may be easier to die, respawn and run back to the boss.

All players both melee and ranged need to be careful for the White Lightning AOE circles. Every 30 seconds light white circles will spawn under random players, you will only have 5 seconds to move before bright purple lightning activates in the circle, making part of the floor around the boss deal damage if you stand on it.
This can be hard to see on Hoth due to blending into the snow.

Overseer Qezzed

Overseer Qezzed

Overseer Qezzed spawns on Coruscant in the Justicar Sector. He is found in a corner towards the South of the map in a corner, surrounded by Justicar Heavy troopers.
X 870 Y 4590

Overseer Qezzed drops 1 Dark Side Token as loot when defeated.

Strategy

Overseer Qezzed has two mechanics that need to be avoided, he alternates using both of them although they can happen at the same time.

Melee players and tanks need to avoid the Large Yellow/Orange rectangle that covers a large area across the boss themself, when the yellow circle under the boss fully charges up to the edge the entire Large Yellow rectangle will deal massive damage for a few seconds.
This can be hard to see on Tatooine and Hoth due to blending into the ground, as it has been pictured above.

All players both melee and ranged need to be careful for Light Blue Lightning circles. Every 30 seconds light blue circles will spawn under 12 random players, you will only have 5 seconds to move before several lightning bolts strike every circle.
Getting hit by one lightning circle will not kill you, getting hit by two or multiple at the same time will.
This can be hard to see on Hoth due to blending into the snow.