Easy as the new Easy Fatality command. :p
Essentially just play a Ladder Tower (which in layman's terms is basically Arcade Ladders of old) of any of your choosing. There's Traditional (10 enemies and two bosses, Goro and Shinnok), Test Your Luck, etc.
Choose one and play/win every match in the ladder to get the achievement. Be sure to hit fatalities as well as good combos. It gives more koins and more XP for other unlockables/achievements.
Good luck.