Enter the Golden Wood

At the beginning of each player's second
main phase, if there is a total number of
three or more +1/+1 counters on creatures
that player controls, exile Enter the Golden
Wood. If you do, that player may distribute
three +1/+1 counters among one, two, or
three target creatures, then double the
number of +1/+1 counters on each of those
creatures.