During each player's upkeep, count the number of permanents. If that number is odd, all red creatures get +1/+1 and mountains produce an additional {R} when tapped for mana until end of turn. If the number is even, all red creatures get -1/-1 and mountains produce colorless mana instead of their normal mana until end of turn.

• Number: 49
• Rarity: R
• Type: Enchantment
• Mana cost: 3R
• Color: Red
• Artist: Drew Tucker