diff --git a/panther/db/models.py b/panther/db/models.py
index 8441a62..a4aebb4 100644
--- a/panther/db/models.py
+++ b/panther/db/models.py
@@ -21,7 +21,7 @@ def validate_object_id(value, handler):
         else:
             try:
                 return bson.ObjectId(value)
-            except bson.objectid.InvalidId as e:
+            except Exception as e:
                 msg = 'Invalid ObjectId'
                 raise ValueError(msg) from e
     return str(value)
diff --git a/panther/db/queries/mongodb_queries.py b/panther/db/queries/mongodb_queries.py
index 5e2f10e..59bf2a7 100644
--- a/panther/db/queries/mongodb_queries.py
+++ b/panther/db/queries/mongodb_queries.py
@@ -102,21 +102,35 @@ async def delete_many(cls, _filter: dict | None = None, /, **kwargs) -> int:
 
     # # # # # Update # # # # #
     async def update(self, _update: dict | None = None, /, **kwargs) -> None:
-        document = self._merge(_update, kwargs)
-        document.pop('_id', None)
-        self._validate_data(data=document, is_updating=True)
+        merged_update_query = self._merge(_update, kwargs)
+        merged_update_query.pop('_id', None)
 
-        for field, value in document.items():
-            setattr(self, field, value)
-        update_fields = {'$set': document}
-        await db.session[self.__class__.__name__].update_one({'_id': self._id}, update_fields)
+        self._validate_data(data=merged_update_query, is_updating=True)
+
+        update_query = {}
+        for field, value in merged_update_query.items():
+            if field.startswith('$'):
+                update_query[field] = value
+            else:
+                update_query['$set'] = update_query.get('$set', {})
+                update_query['$set'][field] = value
+                setattr(self, field, value)
+
+        await db.session[self.__class__.__name__].update_one({'_id': self._id}, update_query)
 
     @classmethod
     async def update_one(cls, _filter: dict, _update: dict | None = None, /, **kwargs) -> bool:
         prepare_id_for_query(_filter, is_mongo=True)
-        update_fields = {'$set': cls._merge(_update, kwargs)}
+        merged_update_query = cls._merge(_update, kwargs)
+
+        update_query = {}
+        for field, value in merged_update_query.items():
+            if field.startswith('$'):
+                update_query[field] = value
+            else:
+                update_query['$set'][field] = value
 
-        result = await db.session[cls.__name__].update_one(_filter, update_fields)
+        result = await db.session[cls.__name__].update_one(_filter, update_query)
         return bool(result.matched_count)
 
     @classmethod
diff --git a/panther/db/queries/queries.py b/panther/db/queries/queries.py
index e06eee0..cba2b6d 100644
--- a/panther/db/queries/queries.py
+++ b/panther/db/queries/queries.py
@@ -364,8 +364,6 @@ async def find_one_or_raise(cls, _filter: dict | None = None, /, **kwargs) -> Se
 
         raise NotFoundAPIError(detail=f'{cls.__name__} Does Not Exist')
 
-    @check_connection
-    @log_query
     async def save(self) -> None:
         """
         Save the document
@@ -384,8 +382,14 @@ async def save(self) -> None:
             >>> user = User(name='Ali')
             >>> await user.save()
         """
-        document = self.model_dump(exclude=['_id'])
+        document = {field: getattr(self, field) for field in self.model_fields_set if field != 'request'}
+
         if self.id:
             await self.update(document)
         else:
             await self.insert_one(document)
+
+    async def reload(self) -> Self:
+        new_obj = await self.find_one(id=self.id)
+        [setattr(self, f, getattr(new_obj, f)) for f in new_obj.model_fields]
+        return self
diff --git a/panther/serializer.py b/panther/serializer.py
index f7bf980..d6fae02 100644
--- a/panther/serializer.py
+++ b/panther/serializer.py
@@ -65,8 +65,8 @@ def check_config(cls, cls_name: str, namespace: dict) -> None:
 
         # Check `model` type
         try:
-            if not issubclass(model, Model):
-                msg = f'`{cls_name}.Config.model` is not subclass of `panther.db.Model`.'
+            if not issubclass(model, (Model, BaseModel)):
+                msg = f'`{cls_name}.Config.model` is not subclass of `panther.db.Model` or `pydantic.BaseModel`.'
                 raise AttributeError(msg) from None
         except TypeError:
             msg = f'`{cls_name}.Config.model` is not subclass of `panther.db.Model`.'