How do you get Liu Kang's fireball?

Once back above ground, open the gate ahead of you at (-1,16) for 2,000 Koins, then head immediately to your right and use Kenshi's Katana at the bottom of the steps to enter Shao Khan's Tomb. The Dragon Fireball can be retrieved from the center of the room if you descend the stairs inside the burial chambers. The year ended on Dec 15, 2015.