Lost Souls: 5
Doors: Argent, Copper
As soon as the mission starts, jump back to reach the old man to chase away the harpies. Follow them inside the station then make your way to the opening to the left. There's an angelic web across but ignore it for now since you don't have the means to reach it. Destroy the red crystals and proceed. Head to the next room and destroy the red crystals to find a small vitality star.
Pull the concrete piece across then boost yourself to the tunnel. Head out to the train tracks and turn to the left to find a lost soul. Continue along the tracks and evade the incoming trains. Once you've reached the open area, take out the enemies then jump to the main opening first.
Enter the gate to the immediate right to find more red orb sacs and destroy the angel web to proceed. You'll find another argent key at the end.
Backtrack then enter the opening to the left this time. Destroy the two shards along the way and destroy the crystals at the end of the stairs. Exit to the next tunnel and use the divinity statue if you want. Continue ahead then jump to the alcove to the right to find a lost soul. You can find an argent door behind the damaged door as well.
Argent Door and Lost Soul, Eyeless
Exit out and follow the tunnel. Destroy the shards that will appear ahead and continue to the dome. Before pulling the eye in the middle, look around and enter the tunnel leading to Platform 1 to find another lost soul. There's another lost soul in the tunnel leading to Platform 2 so don't forget to free it as well.
Take out the pathos and harpies then go through the tunnel leading to the exit. Backtrack to the stage's entrance to hand over the eye you have recovered to complete the mission.