You will spawn in space, so turn left and jump across to the ship's ledge. Keep going left and hopping from platform to platform, and remember to look up if you think you've reached a dead end. Soon, you will find an open vent, so head inside. and follow the path. Shoot the vent and jump down to get on board of the Glykon. Go straight, take the first left, and shoot another vent door. At the end of this room, jump on the upper level and go all the way left. Destroy the floor below you, drop down and go straight. Pull the lever on the right side to open the hangar door, but don't go in. Instead, go left and you will find yourself in a room infested with weird spores. Shoot them to get Egregore Link buff which lets you pass to the other room. Go up, jump across to the pipes on the left, and break into another vent. Keep following the path, traveling to the upper level, before dropping into a room with electric discharge.
Go right, and you will be swarmed by Corrupted Screebs. Make sure to keep the distance when you destroy them, as they will explode and inflict massive damage. Activate the lever at the end of the room and go back to the main room. Destroy spores and jump across the chasm, go left, and then down. Defeat Screebs, go up the vent, get more spores, and jump to the other side. Destroy the switch to open the hatch below you and prepare for another wave of ads. Go right and look for the way up where you will activate a lever. Come back down and destroy a fuse on the left. Go straight, take the first vent on the left, and jump to the other side to get to another lever. This will disable electricity, so fall to the platform below and go through the narrow doorway.
Activate the lever at the end of the hall. This will move the floor beneath you, revealing steel cages. 3 of them have fuse boxes that you'll need to destroy. Next, go down the vent in the middle and follow the path till you drop on the lower level. This is where you will encounter Locus of Communion . Immediately, he will spawn a ton of enemies, such as Ravagers, Raiders, and Corrupted Chieftains. Focus on damaging him first until he flees and then clear out the room. Head through the door on the other side and stay on the left side as you go across the darkly lit hangar to another no-respawn zone. Nasty flame turrets will spawn near you, so eliminate them first. A lot of Raiders will attack from above, so it's best to use objects around you as a cover and take them out slowly. Another huge wave will spawn, led by 2 Darkmind Abominations. They are very powerful up close, so take them out from a distance. It's best to take them out from the platform on the right.
Go to the end of the arena and jump on the platform on the left. Head in another hangar, climb all the way up and go into the vent. Follow the path till you drop down into a ravaged laboratory. Activate the lever on the left to open the door next to it. Destroy spores to get the buff and head through the door on the far right. Clear out Screebs, destroy the fuse on the left, and activate the lever at the end of the room. Jump on the upper level, pull both levers, and drop down. Go left to pick up spores and through the door on the right.
Clear out Corrupted ads and pull the lever that will open the door below. Destroy Scorpius and the fuse next to him. Go up, take spores, and descend down the hatch on the left. Go through the vents and keep repeating the same gameplay mechanics with spores, fuses, and levers. You'll eventually come to the room with rotating platforms, so time your jumps and work on opening top doors. Head back to collect spores, and go into this room to keep the buff, before you jump across and take the path that was previously blocked. Drop through the hatch at the end of the room and prepare for a boss fight.
Locus of Communion
Keep damaging the Locus until he retreats. This will trigger a wave of ads, so clear them out. Locus has teleported on the level below, but this area is too hot. To cool it down, you have to interact with 3 consoles. First, go to the 2 consoles located at the far ends of the arena. The last one is located in the heated room in the middle, so you will have to act quickly as you will accumulate damage. It's recommended that you have a high resilience or some way you can heal. Once all 3 consoles are activated, it's time for a damage phase. Drop down from one end of the room and keep shooting at Locus. Keep distance as he does massive damage, and his ground smash can instantly kill you.
When you damage him enough, the room will grow red, which is a sign that you should get out asap. Clear out ads and repeat the whole process. He will wait for you in the part of the room where you last fought, so it's a good idea to drop from the side that's furthest away.