diff --git a/Editor/Core.cs b/Editor/Core.cs
index 1e437da..c282620 100644
--- a/Editor/Core.cs
+++ b/Editor/Core.cs
@@ -49,6 +49,12 @@ namespace gay.lilyy.SoldAvatarBootstrap
                 AssetDatabase.DeleteAsset(definition.FXLayerPath);
                 AssetDatabase.Refresh();
             }
+            var directory = System.IO.Path.GetDirectoryName(definition.FXLayerPath);
+            if (!AssetDatabase.IsValidFolder(directory))
+            {
+                System.IO.Directory.CreateDirectory(directory);
+                AssetDatabase.Refresh();
+            }
             var newController = AnimatorController.CreateAnimatorControllerAtPath(definition.FXLayerPath);
             if (originalGuid != null && System.IO.File.Exists(metaPath))
             {
@@ -70,8 +76,23 @@ namespace gay.lilyy.SoldAvatarBootstrap
         {
 
             var allLayerGroups = LayerGroup.Instances.ToList();
+
+            var definitionsToProcess = new HashSet<AvatarDefinition> { definition };
+            var definitionsToExpand = new Queue<AvatarDefinition>(definitionsToProcess);
+            while (definitionsToExpand.Count > 0)
+            {
+                var current = definitionsToExpand.Dequeue();
+                foreach (var extended in current.Extends)
+                {
+                    if (definitionsToProcess.Add(extended))
+                    {
+                        definitionsToExpand.Enqueue(extended);
+                    }
+                }
+            }
+
             var layerGroups = allLayerGroups
-                .Where(lg => lg.TargetDefinitions.Contains(definition))
+                .Where(lg => lg.TargetDefinitions.Any(definitionsToProcess.Contains))
                 .ToList();
 
             // Start overall timer
@@ -81,6 +102,11 @@ namespace gay.lilyy.SoldAvatarBootstrap
             GameObject root = null;
             foreach (var candidate in GameObject.FindObjectsOfType<VRCAvatarDescriptor>(true))
             {
+                if (PrefabUtility.IsPartOfPrefabAsset(candidate.gameObject))
+                {
+                    continue;
+                }
+
                 if (definition.IsApplicable(candidate.gameObject))
                 {
                     AvatarLogger.LogInfo($"Found suitable avatar: {candidate.gameObject.name}");
@@ -94,6 +120,12 @@ namespace gay.lilyy.SoldAvatarBootstrap
                 return;
             }
 
+            // If the avatar is part of a prefab instance, use the instance root so we create overrides.
+            if (PrefabUtility.IsPartOfPrefabInstance(root))
+            {
+                root = PrefabUtility.GetNearestPrefabInstanceRoot(root);
+            }
+
             // Skip if the root GameObject or the component itself is disabled
             if (!root.activeSelf || !root.gameObject.activeInHierarchy)
             {
@@ -177,7 +209,8 @@ namespace gay.lilyy.SoldAvatarBootstrap
             AvatarLogger.LogInfo($"Average per layer group: {(processedCount > 0 ? totalLayerGroupTime / processedCount : 0)}ms");
 
             // replace the animator controller
-            var animatorControllers = root.GetComponent<VRCAvatarDescriptor>().baseAnimationLayers
+            var descriptor = root.GetComponent<VRCAvatarDescriptor>();
+            var animatorControllers = descriptor.baseAnimationLayers
                 .ToList();
             animatorControllers.RemoveAll(layer => layer.type == VRCAvatarDescriptor.AnimLayerType.FX);
             animatorControllers.Add(new VRCAvatarDescriptor.CustomAnimLayer
@@ -185,7 +218,12 @@ namespace gay.lilyy.SoldAvatarBootstrap
                 type = VRCAvatarDescriptor.AnimLayerType.FX,
                 animatorController = assets.fx
             });
-            root.GetComponent<VRCAvatarDescriptor>().baseAnimationLayers = animatorControllers.ToArray();
+            descriptor.baseAnimationLayers = animatorControllers.ToArray();
+
+            if (PrefabUtility.IsPartOfPrefabInstance(root))
+            {
+                PrefabUtility.RecordPrefabInstancePropertyModifications(descriptor);
+            }
         }
     }
 }
\ No newline at end of file
diff --git a/Editor/Definition.cs b/Editor/Definition.cs
index c8892a1..868c28d 100644
--- a/Editor/Definition.cs
+++ b/Editor/Definition.cs
@@ -11,9 +11,12 @@ namespace gay.lilyy.SoldAvatarBootstrap
 
     public static IEnumerable<AvatarDefinition> Instances => instances;
 
+
+
     public abstract string DisplayName { get; }
     public abstract string SystemName { get; }
     public abstract string FXLayerPath { get; }
+    public virtual AvatarDefinition[] Extends => new AvatarDefinition[0];
 
     public abstract bool IsApplicable(GameObject avatarRoot);
   }