Witch

Pay {g}- This creature gets +0/+2
Pay {b}- Target creature gets -2/-0
Pay {1}{b}{g}- Target player receives an
emblem with "this card enters the
battlefield with 3 time counters on it,
when the last time counter is removed,
sacrifice this card. If this card is in your
battlefield at the beginning of your
upkeep, take 1 damage."