Artois, if you have a creature that's poisoned or debuffed OTHER than antimatter, fate egg is still better. You're going to end up with a fate egg anyway, and the egg itself costs less time quanta, plus you keep your creature until it dies. I suppose if you want to avoid triggering an enemy Boneyard...
The only non-redundant use of this card, other than to counter antimatter, is against enemy creatures. In which case the "more powerful spell" would give the enemy a regular fate egg, not an elite one.