Instructions
Jump onto the exposed beam to the left of the entrance area -- don't bother walking across the bridge as the opposite side is blocked by a lava waterfall. Climb down the vines and slide across the exposed beams to get to a lower platform with an inert bomb.
Pick up the bomb, jump down to the platforms floating in the lava and follow their path to a red crystal. Throw the bomb onto the crystal, then aim your Crossblade so it targets the torch near the red crystal, then targets the inert bomb. This will imbue the Crossblade with fire, which will light the bomb.
Jump to the area that was blocked by the red crystal and jump to the upper platform to get the Soldier artifact. Backtrack to the entrance area, then activate the lever to the right of the bridge's opening -- this makes the bridge and center platform rotate.
Jump onto the bridge while it is rotating and ride it to the platform with the inert bomb to the left and the active bomb that is just out of reach on the upper wall. Go into the hall where the active bomb is to find a red crystal to the right.
Create a path of inert bombs leading from the active bomb to the crystal -- three or four well-placed bombs will do the trick. Throw your Crossblade at the active bomb to set it off, which causes a chain reaction that ultimately destroys the red crystal.
Enter the room that the red crystal was blocking and activate the lever to raise an angel statue on the side of the lava waterfall. Exit the room and grab an inert bomb on the way out -- carry it to the platform directly across from you, where you can see red crystal flanked by two small torches.
Throw the bomb at the red crystal. Imbue your Crossblade by targeting the torch, then the bomb. Enter the room and activate the lever to raise a second angel statue. Run to the center platform and wait for one of the bridge arms to make connect you to the platform where the lava waterfall is located.
Aim your Crossblade to target both of the crystals that the angels are holding. This cuts off the flow of lava. Grab the crystal sword from the room and run across the bridge to get back to this area's entrance. Exit the area to get back to the room with the three angel statues.