Search for Red Legion Psions drawing power from the Dark Forest's corruption, and eliminate them.
- Go forward, out of the train tunnel into the Dark Forest.
- Ahead you will be able to see a Psionically Enhanced Centurion and a Corrupted Bonded Psion.
- Defeating the Psion will briefly stun the Centurion nearby but unleash a Taken Blight from within the Psion.
- Destroy the Centurion, then, optionally, deal with the Taken Blight.
- Go up the slope and look to the left to find another pair of a Psionically Enhanced Centurion and a Corrupted Bonded Psion.
- You can also just head a bit down hill from your first encounter.
- Go forward along the path and head into the Portal that will appear in front of you.
- Through the portal, you will see a number of Legionaries in front of you.
- Defeat the first group and continue along the path deeper into the Forest.
- Before long you will find a second group of Legionaries to deal with.
- Fight through them and continue forward to the first large pool of water.