Make sure you have it on Night Warriors
and make sure you do this BEFORE entering Arcade Mode:
-At the Menu go to "Help & Options"
-Then go to "Game Options"
-Set the Difficulty to 1 star
-Set the Damage to 9/Full stars
-Set the Rounds to "1"
-Back out then go to "Single Player" and then start up "Arcade Mode"
-Character: Zabel/Lord Raptor or Pyron
You don't really need to change anything else unless you want to nothing affects this achievement with settings.
If you are like me kind of n00by at the game I would suggest using Lord Raptor for this and using "RB" and "Right Trigger". These are his long range attacks cheap and quick. Even if playing on normal like I did and the default way you should win with him all the way just play smart and randomly put combos in or mash buttons your choice.
If you are going for the "God Like" Achievement:
You can use "RA1NKING" soultion and keep using Pyron's Hadoken Fire Ball attack while you are in a far corner.