That last phrase is key. In all the stories, Aslan has permitted and allowed (and even ordained and guided) evil actions and events. The White Witch’s triumph, the Telmarine conquest of Narnia, Shasta’s entire story—all of these were governed by the wise paw of Aslan for the ultimate good of his people. The situation in The Last Battle is very different. To Tirian, Aslan is not merely ordaining that evil exist; he is calling evil good. Aslan has come, but he is not Aslan. It is not unlike those dreams in which someone you love suddenly turns into something horrible right before your eyes.
