Prince of Persia

To get to the Alchemist fro the final battle you have to cleanse all the Sites in his region. Then Elika can open the gate. To move around the Observatory you will need the red and green plates active (which you need to get all the sites cleanse anyway. When fighting him it is important to remember the corruption around the ring at times. If you are pushed into it, you will go into an X-button mash. If he goes into it, he will sink in and come out near the center. Watch his state to know how to attack him.