On one side of the room, there will be a mirror, which you can move by sliding it up or down. Pull the mirror away from the gate so that it unlocks the set of doors with the Sun on them. Proceed down this hallway until the gates close, and you have to kill enemies to proceed. You will get a large mirror. Place this mirror on the empty stand in the main room. Go down the hallway by this mirror, and turn the large mirror until it opens the sun door near it. Go down this hallway until you reach a gate. Shift to the Spectral Plane and pass through the gate. There will be a short cut scene, which hints at the exit to this area. Climb up the pillars until you are high enough to glide to the exit. Proceed until you reach the Blue Portal, located on the left side of a long hallway. Shift back to the Material Realm. Head back to the room with the Pillars. Activate the Soul Reaver, and recharge it with the Dark Reaver power. Now, head back to where the exit you glided to is. The block in the wall between the two staircases can be dragged. Drag the block out, climb up, and proceed down the long hallway again. Head left at the end, defeat the guards, and plunge the Dark Reaver into the Altar. This will create another Dark Bridge. Head across it, and fight the Guards in the room at the end. Now you have the second small mirror, now jump down to the room below and place the mirror on the holder. Now head back to the main room, and back to where the mirror that slid up or down is. Slide the mirror down away from the sun door, so it shines on the other mirror. Now, head down the hallway across from the mirror, glide across the gap. Now, use the Dark Reaver to open the door. That solves the first part of the Light Forge Puzzle.

Head back to the room with the pillars and now, you can open the Dark Reaver gate that you had to pass through before. Head back down the long hallway, past the large mirror, and Glide across the gap, to where the statue with the Dark Reaver symbol is. Now, use the Dark Reaver. There will be a short scene with the statue lowering into the ground. Now, turn the Large Mirror so that it shines onto the Small Mirror on the other side of the gap there will be a short scene to let you know they're lined up right. Now cross the gap again, and use the Dark Reaver to open the door that the Small Mirror is shining on. This will cause it to shine on another mirror, and solve another part of the Light Forge puzzle. Head towards the gate in Light Forge Room the first gate you passed through. There will be a short scene and the gate will open.

Now, head back up the long hallway to the room where the Sentry Eye is where you used the Blue Portal and saw the guy get zapped by the beam. Use the Dark Reaver to shoot a projectile into the eye its located over the Sun Symbol, on the Ceiling. Once the eye is blinded by darkness, run forward and grab the sun symbol. Now, the eye will roll back, so get out of its range as fast as possible. If you get hit, you'll shift back to the Spectral Realm, and will have to shift back to the Material Realm, and recharge the Dark Reaver in the Pillar Room, and do this all over again. Now, run down the long hallway, with the sun symbol, back to the room with the Light Forge in it. Stand in front of the Light Forge, and place the sun symbol on the spot that looks like a sun. After a short scene, you will be in control of Raziel again. Walk forward, and thrust the Soul Reaver into the Light Forge. After another scene, you will have the Light Reaver, and a larger health spiral. Proceed to the door located behind you, and thrust the Light Reaver into it. It's time to make our way out of the Light Forge, and back to the Southern Lake. Pass through the door you just opened, pass by the Light Reaver recharger, and open the Gate behind it using the Light Reaver. Pass through the room with two staircases the one with the Dark Reaver Altar which activates the Dark Bridge and shoot the symbol over the door with the Light Reaver there is a short scene which hints at this. This will open the doors in front of you. Head down the hallway, and use the Soul Reaver to open the doors in front of you, allowing you to go back to the Southern Lake.