Mutant Deity Fortification, Grysfort

-Opponent Turn's Guard Step-[Choose a card with "[Heal] Heal" from your hand, and discard it] Call this card to your from face down. :When placed on during the battle that your vanguard was attacked by your opponent's vanguard, 1, all of the units in your opponent's back row, and this unit gets +5000 for every two of your opponent's units in until end of that battle.