What this does: The current problem with DoD? They have to lackluster win cons. The first is the win con "Make the game take forever". The second is, hope your single avatar can carry the game. Unfortunately for them, when things are going great for DoD in the late game they tend to have a lot of creatures with low power but high hp... They'll have dominant board control...And then The calamity hits effectively ruining the game for them. The solution? Give them a way to quickly deal a finishing blow while still retaining that vulnerability to a board wipe.
Purity: 3p DoD
When you play Sally Forth, the hp of your fortress becomes 1. Swap the HP and Power of ALL non-spirit creatures you control, and move them all to the attack zone. Move all creatures your opponent controls to the defense zone. Until the end of the turn, Non-Spirit creatures you control deal double damage to the enemy fortress. At the start of the next turn your fortress loses 1 hp.
"Sometimes, patience must give way to haste."
Sally Forth literally becomes an all-or-nothing attack, giving the player a chance to turn their stall into a win condition or lose in the attempt. Because of the nature of the card it allows DoD something which they haven't really had access to - mind games against cards such as Mass Death and Fear (That's right, a counter-play against Fear!). Plus, it makes DoD a stall faction without forcing them to stall the game out so long that everybody stops caring.