I had to wait for the fear's embrace nightfall, and I went into the portal that opened up in the ceiling right before the fight with Bongo Bongo, take the airship back to Midgar where you have to forge a diamond pick axe so you can mine for obsidian, then I had to use my shout ability to kill a dragon while simultaneously taking an arrow to the knee, met up with my boy three dog, and then we had to get the leaf so we could get the raccoon armor so we could fly for short distances find the flute and get teleported back to Phobos to fight the actual darkness. Then I did vault of glass and got Vex mythoclast.