The key thing is that you are unprepared for it.
If you use this card, you are designing a specific strategy around it.
You're not just throwing it into a deck.
This means that you can use it flexibly enough to counter anything your opponent throws at you.
Consider Phoenix/Cremation.
Phoenixes have the ability to revive after they are killed, so you can just revive them afterwards.
Cremation gives you the ability to gain quanta even if all your pillars were destroyed.
This gives you a significant strategy to beat your opponent with.
Also, this is a card which has a great amount of power end game.
The idea is to set up everything, and just when they are about to win or gain a large advantage over you, you can use this to gain it back.