The Abandoning of Kamigawa

"After the second great Kami war, it left Kamigawa
barren and desolate. Though its arcane magic remains,
none remain to use, nor the Samurai, nor the Kitsune,
nor the spirits, and nor the wizards. The Phyrexians
followed, and pushed this plane into chaos. Shortly
therefore after, we left to the spiritual realm."