What card do I need?

What card do I need to defeat Demonseed. What card do I need to put in my mage deck.
Or is there no way to beat it? And if that is the case…WHAT WERE THE DEVS THINKING?

Quest druid counters Demon seed. YOu can also play demon seed and you will quickly learn what counters it.

How do I beat it with my mage?