In the original Ogre Battle, March of the Black Queen, you could use Tarot cards in battle to help you out. Elem Pedras do just that. They do no have the vast varying effects the Tarot cards had, but they can unleash quite a bit of damage onto your opponent. Unlike in the Super Nintendo game, Elem Pedra's can not be used when ever you feel like it. When you can use they is determined by the interrupt gauge. This gauge fills up during the battle and must be completely filled 3 times in order to use an Elem Pedra. At the start of the game this is very hard to do, but as you progress the battles get longer and thus you can use the Elem Pedras more often. There are 6 to collect in the game; Fire, Water, Wind, Earth, Virtue, and Bane. At the start of Ogre Battle 64 you can choose an element for your main character Magnus. His element determines what Elem Pedra you will be given, fire with fire, water with water and so on. Virtue and Bane are not available at this point, since no character can have them as their element. But later on you can pick them all up if you know where to look. To the right is the fire Salamander, one of the many avatars that are summoned when an Elem Pedra is used. Each character is ruled by one of the four elements. The four main Goddess to these elements are Zoshonel the Fire Goddess shown top left, Grueza the Water Goddess top right, Harnella the Wind Goddess bottom left, and Berthe the Earth Goddessbottom right. None of the Goddess or Gods are seen directly in Ogre Battle 64, only a shadow of them is seen behind the Elem Pedra they control in the menu.
"How to Unlock 1st Pedra: Choose at the start of the game. You must train Magnus' unit at least 5 times at the following locations and beat the unit with the Venerable dragon in order to obtain the Elem Pedra. If you lose, you have train at least 5 time again at that location before the battle will appear again. 2nd Pedra: Train a unit at Mylesia after Mission 4. 3rd Pedra: Train a unit at Mount Ithaca after Mission 15. 4th Pedra: Train a unit at Gules Hills after mission 20. To get the Pedras you must train your units at a certain location 5 times." Information Taken from www.GameFAQS.com
You must train with Magnus
Virtue and Bane
Besides the four main Pedra, you can also unlock two others from side quests in the game. These two elements, or rather attributes, control alignment in the game. Alignment changes how people speak in the game, and also determine what classes they can change into. Alignment can be changed, unlike a characters element. The Goddess of Virtue Ishtar (bottom left), and the God of Bane Asmodee(bottom right).
"How to Unlock the Pedra of Virtue After Mission 20 go to Gulus Hill, Muji. Talk to a guy about his daughter. Then go to Volmous Mine, Volmous Mine and learn that the guy\'s daughter is at Mount Ithaca. Go to Mount Ithaca, Caltovich and give her fathers letter to her and in return she will give you the Pedra of Virtue.
How to Unlock the Pedra of Bane After Mission 12, go to Soathon, Jiram. Get some info about a missing dog. Then find a Hellhound and go back there. Give the kid a Hellhound and he will give you the Pedra of Bane."