Realm - Outworld / Coord. - H - 8
Accept Cage's challenge then exit from it and re-enter untill you manage to get Liu Kang ( if you have him unlocked; if you don't Li Mei was the second best one I used, I got up to 11 hits ) use this combo to beat the challenge ; X - X - Forward + Y - Away + X - Down, Forward, A. The key is timing Liu's bicycle kick. Sadly, nothing happens after you accomplish the combo. It sucks if you ask me. I thought it would unlock him or reveal a key or something.