Priest of the Haunted Edge

{T}, Sacrifice Priest of the Haunted Edge: Target creature gets -X/-X until end of turn, where X is the number of snow lands you control. Activate only as a sorcery.

Steeling Stance

Creatures you control get +1/+1 until end of turn.
Forecast — {W}, Reveal Steeling Stance from your hand: Target creature gets +1/+1 until end of turn. (Activate only during your upkeep and only once each turn.)

Haunt of the Dead Marshes

When Haunt of the Dead Marshes enters, scry 1.
{2}{B}: Return Haunt of the Dead Marshes from your graveyard to the battlefield tapped. Activate only if you control a legendary creature.