An easy way to complete this is to use Sheeva and another character you're comfortable with in a Tag Ladder. Have the timer set to 30 seconds and have it set for one round wins.
Once ingame you'll mainly want to do nothing but spam Sheeva's stomp
, This move is unblockable and the A.I. doesn't do a great job of trying to avoid it, and you can easily defeat enemies on MAX through timeout.
Only Shao Kahn should give you much trouble, but it's very easy to projectile spam on Kahn even on MAX so use either Sheeva's fireballs or if your tag partner has a projectile use that instead.