There is a Good FAQ/Guide on GameFAQ
For some reason there’s all of one hard fight in the game (for most people), and you’re on it. After that you have enough points to spend between fights that nothing’s really challenging…
As far as I remember, there are only two tricks to keep in mind.
- Keep the initiative. As long as you keep the initiative, your opponent won’t get any chance to hurt you. This means boosting the appropriate stat (I think it’s Agility or something like that).
- Each color is strong against one and weak against another. Your color is determined by the card you put on the field, more exactly by the sum of the numbers on those cards (for example, I put down a red 4, a red 5 and a blue 8, red is 4+5=9, blue is 8, the resulting color is red). Always try to get on the board the color that’s strong against the opponent’s color (it doesn’t matter if this means not using all your cards - they will get stronger later anyway). Using this, you should be able to outpower the opponent using always one card less (and this is particularly important during the initiative phase, since one card less used there can be used later to put more damage).
If you stick to these two points, you should easily be able to win all the matches in the game. I don’t remember losing any match, and even Angela only managed to put one hit against me during the whole fight.
Breezed through the battles here. The game needed a hard mode. Pathetic compared to the card battles in NineTail’s games (Kikaijikake no Eve and Amatsukaze).
Another thing to consider is that you can choose to enter the fight on “easy” mode and have your stats jacked up automatically. There’s no penalty for doing so other than you don’t get much EXP, but I seriously doubt you would need it even by endgame.
Actually, if I recall correctly, the only penalty for using easy mode is that you don’t get extra XP for finishing the battle in under a certain number of rounds or doing excessive damage over what is required to finish off the enemy. Given how long the battle with the Dragon Princess usually takes (in my experience), you normally wouldn’t get the bonus for beating her early, and your stats are so low at that point that you are also unlikely to do much over what is needed to beat her. So in essence, even if you play in normal mode, you will get the same amount of XP as if you had played easy mode.
My walkthrough for the Angela battle: viewtopic.php?f=14&t=5540&p=91239#p91239
That’s the hardest battle in the game. You shouldn’t have much trouble after that, and the same strategy applies to other battles.