This is a fairly easy achievement. If you haven't bought anything, download everything that's free from the xbox store. Restart game, You should have klassic skins for few characters and klassic fatalities. Start Single Fight versus a very easy opponent. Preferably pick Scorpion with Klassic skin. During the Fatality sequence, stand mid range Hold
. Scorpion then should do his magic and you should get the achievement. The fatality name is "Toasty!"
[UPDATE] According to comments, It can also be done in Fatality practice