If you just start playing the game, whenever you get a new card, especailly a powerful one, got to the Menu and choose "edit deck". Your offensive deck will automatically add the most powerful cards, limited by your MP. You may also want to go to your defensive deck and press auto def priority to get max protection.

Remember, use the referral code: URW2551 to get a powerful rare card for both of your attack and defence.

Good luck!

Get a super strong card by entering the referral code: URW2551

Regular Quest:

Adv. : You may get more exp point; it always there

Disadv.: Less cps to get.

Event Quest:

Adv.: You may get more Cps and other high level stuff

Disadv.: You have to finish it within the time limit (usually 2-4weeks) to get the very special items.

Use the referral code: URW2551to get a rare card and it will help a lot.