Clearing all 20 of these Battle Modes should not be too difficult at first. For 17 of the Battles you can continue and select "Retry" if you are ever defeated. This allows you to have a rematch against the opponent who beat you so that you can continue where you last left off. You get as many tries as you need to complete the challenge. The only Modes you will have to clear without being defeated are Survivor, The Max, and Impossible.
Just wanted to point out to anyone reading that Speed Run
makes you restart upon defeat as well.
Well other than that, I really appreciate you posting this. I hope it helps alotta people. I've been using all those methods for a while now and still can't get the Battles done, but I guess I just have to keep getting frustrated with the game and trying time after time again.
Oh, and this is just my suggestion so you don't need to do it, but I'd say repost all that good information in a new thread and call it, "The Ultimate Battler Guide" , that way people can reference it quicker than scrolling through this thread.