diff --git a/avilla/core/ryanvk/staff.py b/avilla/core/ryanvk/staff.py
index adafa718..600e35d5 100644
--- a/avilla/core/ryanvk/staff.py
+++ b/avilla/core/ryanvk/staff.py
@@ -75,8 +75,17 @@ async def query_entities(self, pattern: str, **predicators: FollowsPredicater):
 
         def build_handler(artifact: tuple[BaseCollector, QueryHandlerPerform]) -> QueryHandler:
             async def handler(predicate: Callable[[str, str], bool] | str, previous: Selector | None = None):
-                instance, entity = artifact
-                async for i in entity(instance, predicate, previous):
+                collector, entity = artifact
+
+                def _get_instance(_staff: Staff, _cls: type[N]) -> N:
+                    if _cls not in _staff.instances:
+                        res = _staff.instances[_cls] = _cls(_staff)
+                    else:
+                        res = _staff.instances[_cls]
+
+                    return res
+
+                async for i in entity(_get_instance(self, collector.cls), predicate, previous):
                     yield i
 
             return handler
diff --git a/avilla/elizabeth/perform/event/member.py b/avilla/elizabeth/perform/event/member.py
index 14a06621..567c5cb7 100644
--- a/avilla/elizabeth/perform/event/member.py
+++ b/avilla/elizabeth/perform/event/member.py
@@ -90,7 +90,7 @@ async def member_special_title_change(self, raw_event: dict):
         group_data = member_data["group"]
         group = land.group(str(group_data["id"]))
         member = group.member(str(member_data["id"]))
-        members = await self.connection.call("fetch", "memberList", {"target": raw_event["group"]["id"]})
+        members = await self.connection.call("fetch", "memberList", {"target": member_data["group"]["id"]})
         members = cast(list[dict], members)
         operator_data = next((d for d in members if d["id"] == raw_event["operator"]["id"]), None)
         operator = group.member(str(operator_data["id"])) if operator_data else group