What is the main conflict in The Last Battle by C. S. Lewis?

"The Last Battle" by C.S. Lewis begins by introducing a donkey named Puzzle and an Ape named Shift. They sit on the banks of the Caldron Pool beyond Lantern Waste. Puzzle has been convinced that he is not clever and that Shift should make all of the decisions. The two sit down and see something in the water. The item in the water is a lion skin, which Shift states was sent by Aslan for Puzzle to wear. Narnians would believe that Puzzle is Aslan and they would obey his commands. Shift modifies the lion skin to fit Puzzle.