Thalia:
To tell you the truth, I don't know the details. According to a legend, during the war with Humans who betrayed Elven race, we used forbidden magic. As a result, a vast territory was turned into a lifeless wasteland. Now this infected land is called the Sea of Spores, and it still frows in size. One day the Sea of Spores might devour even our Elven Forest.
And isn't it a bitter irony that Humans are the ones who prevent the Sea of Spores from expanding? I think that the Sea of Spores demostrates the grave foolishness of that Elven decision.