The Mightstone and Weakstone [The Brothers' War Prerelease Promos] SV58 each time it destroys an

each time it destroys an opponent's monster by battle: You can add 1 "Spellbook" Spell Card from your Deck to your hand

and Special Summon 1 "Stardust Dragon" from your Graveyard

First Order Cost: 6

Then if creatures you control have total power 10 or greater

Set: EX: Holon Phantoms Type: Psychic Rarity: Holo Rare Retreat cost: Colorless

The Mightstone and Weakstone [The Brothers' War Prerelease Promos] SV58 each time it destroys anSet: The Brothers' War Prerelease Promos Type: Legendary Artifact Powerstone Rarity: Rare Cost: {5} When The Mightstone and Weakstone enters the battlefield, choose one Draw two cards. Target creature gets 5 5 until end of turn. {T}: Add {C}{C}. This mana can't be spent to cast nonartifact spells. (Melds with Urza, Lord Protector.)