Reveneant Hunter

{3}{u/b}{u/b}{u/b} Silence and Squall: All creature's on
target player's battlefield have a -1/-1 slow
counter, which turns into a Frozen counter
during their upkeep. Reveneant Hunter gains a
+0/+3 counter during this turn.
(Cast only as a sorcery)
{b}{u}{u} Shatterdive: All creatures on a target
player's battlefield with a frozen counter
receive 5 damage. (Cast only as an instant)