Hallowed Haunting is a mythic Enchantment card from Special Guests (SPG), collector number 64. Current market price: $8.03 (foil $10.49), TCGplayer market prices via Scryfall.
As long as you control seven or more enchantments, creatures you control have flying and vigilance. Whenever you cast an enchantment spell, create a white Spirit Cleric creature token with "This token's power and toughness are each equal to the number of Spirits you control."