Ignore the Green Chests for now, as you might need them in a little bit. Jump onto the middle block and push the small block off of it, which will make it rise. This will also make enemies spawn, which pretty much come in three waves. The first wave is a Wraith that can summon shadows, the second wave contains two Satyr Generals and more Wraiths, and the third wave is two Sirens and another Wraith.
After killing them all, grab the movable block and push it to the left. Jump up, open the Red Orb Chest, then pull the lever, which lowers the source of the laser (note the chain). Go back down and push the block to the right side, jumping up, grabbing the Red Orb Chest and climbing the ladder (the laser doesn't hurt). There is a Phoenix Feather and Gorgon Eye up here, so grab them, then hop the gap.
Get on the conveyor and create a clone, then jump back down to the bottom and get on the left side of the area. Grab the chain and pull it to make a receptacle come out, which the white block will rest in. This will cause the laser to line up right and come out the eyes and hit the lantern.
Once you have control again, climb the ladder to your left. At the top, you'll view a cutscene and then get thrown straight into a battle with an injured Manticore. Since it only has one wing, it's not too hard, so wait for it to breathe its fire, then close in to pull off a combo, backing off after that. When it's dead, walk forward for a cutscene.