[Vicious Love]

Ooh. Harsh. Petrify would still work, as would a horde of lifeless chaff supported by lifedrainers, or a high-att Mage Bane wielder. Speaking of which, if gems really aren't a problem at this stage of the game, you could scout out this SC's equipment and Wish for some choice articles right before the battle.

Consider supporting any of the above offhand suggestions with a relatively high-level astral/fire mage scripted to Phoenix Pyre, any reinvigoration spells he may have, and a barrage of Magic Duels. This really doesn't seem like that good a use for an S7 or S8 mage(assuming the enemy SC has base astral 9), but if you like overkill...