The Styx mission, the second Expunge mission, can be launched from the Moon. You’ll be teleported into the Vex network shortly after opening the Director and selecting the mission.
You’ll once again be traversing the Vex network’s winding maze, and much of the same methods from Labyrinth apply: look for hidden pathways, evade any purges the Vex sends your way, and race through the maze until you reach the final portal.
- Read more: How to unlock Destiny 2 Expunge mission
You’ll be thrown into a new area full of Vex structures after passing through the little Vex gate. Similar to the Data Spikes found in Expunge: Labyrinth, Mithrax will notify you that multiple barriers are impeding your path, and you’ll need to destroy a small Vex artifact and pick up the Authentication Key it drops to clear the way.
Use the first key to open a gate blocking your path. Then take the second key from the opposite side. Shoot or navigate your way through the enemies in the next section before reaching a shielded turret with another key slot nearby.
After you’ve deposited the second key, you’ll note that there are two more spots that need to be filled. Clear out the two regions next to the turret room, each of them has another Authentication Key needed to fill those slots. You’ll finally be able to tear down the shield and face off against Dikast, the Oppressive Mind.
The Vex boss will attack you with projectiles while spawning defenses all across the arena. Its barrier will regenerate after being damaged, and you’ll have to take it out with another Authentication Key. Bring down the shield, then finish the boss with another round of damage to complete the mission.
Full Guide: Destiny 2 Expunge guide: How to unlock best Gauntlet upgrades