Buy the Oni called Drahmin (UR, 6500 Sapphire) and play as him. You will start in the Netherealm fighting stance. If you change it to Oni or Iron Club, you should see his real face. Note: You may also need to have bought Drahmin's alternate costume (SW, 1152 Jade) . Have Frost kill Drahmin with her Ice shatter fatality. Drahmin's mask will be all that remains.