Mage of the Last Light

If it's neither day nor night, it becomes day
as Mage of the Last Light enters the battlefield.
Whenever night becomes day, put a +1/+1
counter on this and exile the top two cards
of your library. Until the end of your next
turn, you may play those cards.
{r/w}{r/w}, Remove a +1/+1 counter
from this, {t}: If it's night, it becomes day.