There is an easy way to get this achievement and the following two in just a few minutes. But you will need two controllers for this solution.
Expiration Date260 (20g)
Killer Instinct Gold: Perform five No Mercy or Fatality finishers over time.
Didn't Break a Sweat278 (20g)
Killer Instinct Gold: Get 25 Supreme Victories in Arcade Mode over time.
Go to Arcade Mode, press Start on your second Controller to enter the charakter screen with your second player too. Now both player choose their fighters by holding DOWN and pressing MK (=Medium Kick).
On the Sky Stage you can do an easy Stage Fatality by hitting the enemy with an uppercut. I have chosen Jago for this move. The inputs are:
+ FP or MP (Fierce Punch or Medium Punch)