Hey, I think it would be cool if we listed descriptions of all the so far known fatalities.

So, let's start...
Kira's Torso Rip Kira throws her blades into the feet of the opponent, securing them in place. She walks over and rips their body from the waist up and throws back behind her.
Sindel: Screams sooo loud you blow up. When you do Sindel puts both of her arms on her side and floats up.
Sub: Freezes you walks up rips of your head(spine included) does a feeze slid back and throws your frozen head at your frozen body. You explode beautifully.
Nightwolf: Takes out tomahawk holds it in both hands behind his head and does a power throw. The axe lands right in your head and you stumble and Nightwolf looks up and raises his hand. More later its too late. And so on.
Kenshi's Telekinetic Rack Kenshi lifts you up in the air and then he "parts the opponents seas", but using telekinesis to pull in opponent in both directions. Kenshi makes the split and you've got a spare. Bad joke, I know.
Hotaru's (for now) Sack Attack Hotaru slaps his opponent around like a big fish when grabs them by the leg, slams them on the ground, then rolls them over still by the leg so he can throw them over as Santa would his sack. Eventually they leave a puddle of their battered remains.
Scorpion's (for now) Soldier in Arms Scorpion rips off his opponent's arms and procees to whack them relentlessly with their own anatomy. Eventually a well placed strike knocks off the opponents head.
Mileena's Feast Time Mileena reveals her chompers and digs in on the opponent's neck. She chows through the opponent's tendants until she is able to rip of the remnants and throws the head away. She laughs maniacally.
Mileena's (for now) Home Run Mileena rips off the opponent's leg and proceeds to hit their head for a six (in Australian terms). I guess you could say the opponent reached their last legs (sorry I'm in a punning mood).
Baraka's Kombatant Kebab Baraka slices and dices through his opponent until he stabs in one of his blades and rips their torso out.
Bo' Rai Cho's Boraccho Breath Bo' Rai Cho takes a whisk and then proceeds to blow his flammable, alchoholic liquid into his previously lit flame, which creates a blaze which burns the opponent's head off.
Li Mei's (for now) Fists of Fury Enraged about the bad feedback her character got in MK:DA, Li Mei lets loose with a barrage of rights and lefts reducing the opponent to a pulp.