Go to the upper end and use the skull, once you've done that head back down and go through the red gate that opened. Then search the waypoint marker and go through the cave, in the next area you'll find a lot of platforms rising in the area we started at. Once you're in the next area, you'll have to kill a bunch of demons including Unwilling, Imps, two Summoners, and a bunch of Hell Knights and Hell Razors. Once you've obtained it, head back up the stairs in the last area and interact with the yellow door, inside you'll find a cave which contains an Elite Guard as well as an artifact. Once you've defeated them, jump down to the next floor and interact with the skull to open a door that leads to a yellow skull, which is the demon's equivalent of a yellow keycard.
However once you reach the top of the stairs you can find some rocks leading up to some armor, this counts as finding a secret.ĭrop into the next area and head down the path to find some demons that you'll need to kill.
Then go up the stairs and kill some more at the top. Kill the Unwilling that are on the other side and then pick up the Gauss Cannon if you haven't picked it up yet. Keep going and you'll find some holograms, keep going after them and drop down up ahead. After completing Mission 5: Argent Energy Tower, begin heading down the path and interact with the skull at the end of it.
