Instructions
Baraka
Unlock Baraka in the third area of the Soul Tombs level. There are three Tarkata on the bottom floor. Kill them and proceed to the far wall -- climb it using the "Wall Climb" ability.
Destroy the statue at the top of the wall using the "Fist of Ruin" technique and walk along the path behind the statue.
Jump across the gaps onto the narrow ledges until you get to one with a red Yin Yang symbol on it -- collect the symbol to unlock Baraka.
Johnny Cage
Unlock Johnny Cage at the Wu-Shi Academy after you have completed the first "Test Your Might" mini game.
Walk to the right of the gate and jump onto the roof of the adjacent house. Run to the right and jump just before the edge of the roof to land on a platform.
Explore the platform to find the token that unlocks Johnny Cage.
Kitana
Unlock Kitana in the Evil Monastery, between the where you learned the "Multality" skill and the area with the large portal and two statues.
Walk to the cluster of pillars. Explore until you find a pillar that has been broken in half.
Jump onto the pillar, then double-jump onto the adjacent roof. Explore this area to find the token that unlocks Kitana.
Reptile
Unlock Reptile in the Living Forest just after the "Brotherhood of Shadow" section of the stage.
Jump across the gap that has the small waterfall in it and walk through the door. Walk up to one of the clay statues to make it to come to life. Destroy its shield and grapple with the statue.
Lure the statue back outside, near the large stone column. Grapple with the statue and throw it at the column to destroy it. Go back to the little waterfall to find the token that unlocks Reptile.
Sub-Zero
Unlock Sub-Zero in the Wastelands just after you cross the river in the boat with him.
Explore after disembarking the boat to find two lion statues.
Walk up to the lion statue on the left. Double-jump to get onto its back to collect the token that unlocks Sub-Zero. Alternately, use the "Wall Run" ability to run up the side of the statue to end on its back.
Scorpion
Unlock Scorpion in the beginning of The Foundry, just after the Save Point. Walk along the path to the north until you are ambushed by two archers.
Grapple with one of the archers and throw him through the left wall. Jump through the wall and lure the other archer toward you.
Grab the second archer and fling him into the lava pit, where you should see a token hovering. Jump onto the archer's body to collect the token that unlocks Scorpion.