The Mightstone and Weakstone [The Brothers' War Prerelease Promos] Tribal Artifact Whenever an opponent taps a

Whenever an opponent taps a land for mana

Set: Collectors' Edition Type: Sorcery Rarity: Common Cost: {X}{R} This spell costs {1} more to cast for each target beyond the first

Criosphinx Sovereign or another Sphinx enters the battlefield under your control

where X is the number of cards in your library

Rather than sheltering her young

The Mightstone and Weakstone [The Brothers' War Prerelease Promos] Tribal Artifact Whenever an opponent taps aSet: 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.)