Mortal Kombat 11

Local versus against a 2nd controller or CPU on Very Easy difficulty. Set rounds to win on 1 in the main menu beforehand.

Bring the opponent's health down until its says "Finish Him"

Totem Sacrifice - (close)

Kat Food - (close)

These inputs are assuming you are on the left side of the screen if you are on the right side you will need to invert the horizontal inputs.

Shout with any questions, comments, or concerns.

~ Slayer

In this video guide I will show you how to perform two different fatalities with Kotal Kahn. For the first 10 characters I just used the klassic towers to get the achievement progress for I Want It All. Make sure to put it on very easy to make things quicker. Also pick the shortest tower.
After getting your I Want It All achievement the method with be a lot faster. Once in the main menus press the start button to go into the options menu. Scroll down to change the rounds to win to one. Then back out, go into the fight menu, select local, make sure to press X to turn on the CPU, and then select your character. You only have the one health bar to deal with to get to the fatality.
Achievement progress also counts if AI do a fatality.

Totem Sacrifice (Close) - Back, Down, Back, A
Kat Food (Close) - Back, Forward, Back, Forward, X

In the options (press Select) set number of rounds to 1 and when selecting opponent set AI difficulty to 'Very Easy' (can also use a second controller if available).

Hit the enemy until their health bar is drained at which point 'FINISH HIM' will appear on screen. Position your character in the appropriate spot and input the following commands:

Totem Sacrifice (Close) - Back, Down, Back, A
Kat Food (Close) - Back, Forward, Back, Forward, X

Then when the points are tallied hit 'Retry' to restart and perform the second finishing move.