As Pillar of Origins enters the battlefield, choose a creature type.
: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type.
To choose a creature type, you must choose an existing creature type, such as Vampire or Knight. You canâ€™t choose multiple creature types, such as â€œVampire Knight.â€ Card types such as artifact canâ€™t be chosen, nor can subtypes that arenâ€™t creature types, such as Jace, Vehicle, or Treasure.