Arcana Force XV - The Fiend - Maze of Millennia

You can discard this card; add 1 "Light Barrier" from your Deck or GY to your hand. If this card is Summoned: Toss a coin and this card gains the appropriate effect.
• Heads: When an attack is declared involving this card: You can target 1 monster on the field; destroy it, and if you do, inflict 500 damage to its controller.
• Tails: When an attack is declared involving this card: Destroy all monsters on the field.