How do talent cards work? How do I get magic crystals? How do I get talent cards? Help please!

Prayer Tree is a method of boosting your Battle Rank that is unlocked at level 65 and is accessed through a button labeled "Prayer" on the bottom-right corner of your inventory.     The goal is to sacrifice items to the tree to give the tree experience, only certain items can be sacrificed. Once the tree gains enough experience, it levels up and provides increasing stat boosts to your entire team   These are the only materials the tree seems to accept currently:   Energy Stone I: Star Shard: 60 (costs 6 each) Dragon Blood Armor: 100 (costs 30 each) Dragon Blood Accessory: 125 (costs 40 each) Dragon Blood Weapon: 200 (costs 60 each) Energy Stone II: Ice Crystal: 120 (cost 30 each) Scroll: Armor of Ancients: 150 (cost 90 each) Scroll: Accessory of Ancients: 175 (cost 150 each) Scroll: Weapon of Ancients: 300 (cost 240 each) Energy Stone III: Elven Quill: 180 (cost 100 each) Scroll: Armor of Flame: 200 (cost 300 each) Scroll: Accessory of Flame: 225 (cost 500 each) Scroll: Weapon of Flame: 400 (cost 750 each) Energy Stone IV: ???: (I have not made it this far yet) Diamonds: Diamond, rank 1: 10 Diamond, rank 2: 20 Meteorites: Meteorite, rank 1: 20  Meteorite, rank 2: 40 Mithrils: Mithril, rank 1: 40 Mithril, rank 2: 80