The Mightstone and Weakstone [The Brothers' War] 153a Set: POP Series 8 Type:

Set: POP Series 8 Type: Grass Rarity: Rare

where X is the greatest power among creatures you controlled as you activated this ability

perfect beginning

it gains the following abilities until end of turn

Set: March of the Machine Prerelease Promos Type: Creature — Phyrexian Rarity: Rare Cost: {3}{W}{W} Flying

The Mightstone and Weakstone [The Brothers' War] 153a Set: POP Series 8 Type:Set: The Brothers' War 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.)