Demon of the Night

If you have-
•10 or less Night counters, sacrifice this creature.
•15 Night counters or more, this card gains
flying, trample, and "At the beginning of your
upkeep, you lose 2 life."
•25 Night counters or more, this card gains
nightstrike, and lifelink
{bull}35 Night counter or more, this card gains
protection from white, +5/+5, and "At the
beginning of you upkeep you lose 4 life."