Generate an atmospheric animation of a lone knight sitting under a tree with the silhouette of a distant castle. The soft mist rolls over the hills, partially veiling the castle. The air is calm but the mist slowly shifts and changes. Do not move the camera. Only animate the drifting mist, light flickers in the background, and the soft movement of leaves on the tree. The final frame matches the first frame exactly to ensure a perfect infinite loop with no visible cuts.