You will enter a room that has a group of eyes on the walls. This is the room where the final battle will take place, against Crowley. He is easy to fight. Just attack him repeatedly. Your sword seems to work best. When you can, use your rage. It seems to do a lot of damage to him. Countering his attacks seem to work well, but sometimes he will counter your counter attack. Press the R2(2). You will counter his counter and hit him. After his life bar is empty, he will talk about how he will not give up, and how he has to do this for Elma. He will then use the elixir to turn himself into a giant golem. Watch out for his attacks and let Al help you. Use your sword combos (for example, Square, Triangle(3)) to slash him. He will fall on the ground. This is the time to use the foot swipe. After he is defeated, Roy, Hawkeye, and the man with the muscles will appear and take over, From here, you must destroy the stone. Once in the room with the crimson elixir, Ed will touch the stone and fall unconscious. Somehow his mind will go inside the stone. When you are there, you will be in some sort of white void. Just run to each of the red orbs. They are memories from the King of Lebis, and memories from Crowly and his Elma. Transmute the spikes on the outside of the circle. When Ed and Al transmute it, the stone will break, and Crowley will be defeated to be in peace with Elma.