In Rage of Bahamut your defense deck is a long term money maker/saver. In my Rage
of Bahamut Guide I cover several things as a generality for beginners.
In this portion I will be focused on Defense Decks and the importance of
them.
To begin, the core of your defense deck is determined by your defense points. Every card has a cost attributed to it. Your defense decks total
cost can not exceed your number of attack points. An example of this
would be if you had 100 defense points. You would not be able to have
five 22pt cards in that deck since the total cost would be 110. You
could have three 22 point cards for a total of 66 then two 17pt cards
for a total of 34 to equal a perfect 100.
In your defense deck you should have your cards with the defense
power that you can achieve. If you use the recommended deck option, the
game will automatically figure this for you.
Another part that plays into your defense deck are the skills that your
cards bring to the table. Cards will have a variety of skills. The
skills will focus on either boosting your cards or applying a debuff to
the opponents cards. The buffs you want to look for in your defense deck
are Increase to DEF, Increase to ATK/DEF, Decrease to enemy ATK,
Decrease to enemy ATK/DEF. Your cards skills won't always trigger, so
many attack decks are stacked with five cards with skills to ensure the
maximum chance of them triggering. Also, there are skills that focus on
cards of a specific alignment, be aware that you want to attempt to
stack your alignment to get maximum benefits from these cards.
Defending plays the role in Holy Wars of preventing enemies from gathering points. It also plays the role of protecting your rupies and treasure while gathering rupies. If a player attacks you to steal your treasure and his attack deck fails against your defense deck, you gain up to 10000 rupies.
Defense points are not calculated the same way attack points are. When you are attacked during a holy war you lose only 10 of your defense points rather than the entire amount of the deck. Because of this it may be very difficult to take down a defense leader unless you can arrange several successive attacks within your order. To put it into perspective, if you have 300 defense points and your deck costs 110. Somebody would have to attack you 20 times before you would not be able to use your deck. This would require a lot of organization or the use of large amounts of holy powder by the enemy. This is assuming your defense deck always wins, of course if it's attacked by a more powerful offense deck, you immediately lose.
As you are leveling and not creating your final cards remember that
leveling five cards to level 10 in your deck through enhancement is
better than leveling one card to max. The fastest levels to attain on a
card are the first 10-15, so get five decent cards there then you can
focus on increasing them.