"A Summoning Piece that contains the indescribable powers of light and darkness. You may summon a 3 - 5 Star Light or Dark Attribute Monster."
The Light & Dark Summoning Piece is an item available in the Magic Shop. It costs 135,000~160,000 mana stones for 5 pieces. Using this item requires 50 Summoning Pieces, which amounts to 1.35~1.85 Million mana stones.