Obscura Ascendancy (SNC) from Streets of New Capenna, available at 401 Games Canada.

• Rarity: Rare
• Finish: Normal
• Artist: Igor Krstic
• Card Text:
  Whenever you cast a spell, if its mana value is equal to 1 plus the number of soul counters on Obscura Ascendancy, put a soul counter on Obscura Ascendancy, then create a 2/2 white Spirit creature token with flying.
  As long as there are five or more soul counters on Obscura Ascendancy, Spirits you control get +3/+3.