Just Leave It... Ality
You beat down on the opponent and other cast members try to pull you off them. I know, I know... brilliant.
Testicality
A simple kick to the balls to end the fight would do here.
A serious one would have to be...
Hesitation
Make them beg for mercy and then either deliver the killing blow or allow them to live.

The Hesitation idea is actually cool, they could implement this into the Story Mode to make it replay worthy (MK Mythologies)

Yeah thanks, it's just something different you know :).

I always thought it would be cool to have a double fatalities when doing a Tag ladder matchs with both characters the player has chosen. For an example if a player chose Sub Zero and Scorpion it would be like this. Sub Zero would fress the other player and then Scorpion would slice the other player in half or use his TOASTY on them. What do you all think of that?