Some tips I can give u.
THE WHOLE DEF THING IMO:
keep you def pwr with the cards you have. If your def deck only requires "76 pwr pts" then all you need is "76" def pwr. Adding extra points to your def is nice but IMO add them only when needed. You get a higher card, add the pts at next lvl up. Just keep your def lvl at its peak. You will being getting hit in the treasures portion of the game(rings, keys, medals and so forth) as you try and battle for them. Also if you enter into an order, opposing team will pick on lowest def player.
IMO the extra pts can be better used in your attack and stamina. When building an atk deck, your "Pwr" lvl is taking away from your "Atk pwr" pts. So simple enough, if your sci carries 77 atk pwr and you have 100 atk pts....left with 23 pts after a battle. If you can keep your pts double of your deck, then you can attack twice in what it takes most players one attack in the game.

try and stay with your alignment. You get an extra buff at each battle if you are attacking or defending. But then again, you get some nasty off spec cards and you begin to wonder if you made the right choice.
I hope this help. Please use "qif67760" as your code to get a rare angelic knight card and 100,000 rubies and look me up in game for help if needed "scubasteve72" Always open to entertaining trades for demon cards.
GOOD LUCK AND HAVE FUN!!!