Legendary Artifact (CMC 3)
If it's neither day nor night, it becomes day as The Celestus enters the battlefield.
: Add one mana of any color.
, : If it's night, it becomes day. Otherwise, it becomes night. Activate only as a sorcery.
Whenever day becomes night or night becomes day, you gain 1 life. You may draw a card. If you do, discard a card.