Well, there's your answer, then: CURSE the Sphinx first, THEN try to kill him.
Really, though, killing a Sphinx isn't a battle, it's a demolitions project. The Sphinx is completely immobile now, so there's really no point to taking it anyway: The teleporting Sphinx of Doom is gone. Now it's just a greatly overpriced chassis that doesn't offer anything other, far cheaper immobiles don't, and loses even the ability to teleportate.
[ April 24, 2004, 20:12: Message edited by: Norfleet ]