Christmasters of Tarant

At the beginning of your upkeep, you may put an
ice counter on Christmasters of Tarant.
As long as Christmasters of Tarant has three or
more ice counters on it, all creatures your
opponents control have -2/-0.
Whenever one or more creatures your opponents
control attack, you may give target creature -X/-X
until end of turn, where X is equal to the number
of ice counters on Christmasters of Tarant