Harvest Festival

Choose target creature. For each creature that
died this turn, put a +1/+1 counter on that
creature. If you put ten or more counters on a
creature this way, put an indestructible counter,
a menace counter, and a trample counter on that
creature, and it becomes a Demon in addition to
its other types.

"Notice. The conditions have been met. The Harvest Festival will now begin."