You may pay 6 life and sacrifice three black creatures rather than pay Demon of Death's Gate's mana cost.
Flying, trample

The locks on the cages of the damned are opened with keys of marrow, sinew, and blood.

• Number: 92
• Rarity: M
• Power: 9
• Toughness: 9
• Type: Creature
• Subtype: Demon
• Mana cost: 6BBB
• Color: Black