Eren was informed that a friend was waiting outside the sect who came here to meet him. As he didn't have permission or authority to enter, the guards didn't allow that person inside.
The guards only sent a message to Eren to confirm if the person was indeed someone who he claimed to be.
"Did he give you a name?" Eren asked the Librarian.
Eren was sure that Ren Necroline had no friends in this world. At least that was his assumption. The only person who was even close to Ren Necroline was Devourer but that person was already dead.
"He said his name is Qien. He said you would remember him if you're informed about the ring or something like that? Does that hold any significance?" the Librarian stated.
"The ring?" Eren looked at his hand. There was only the storage ring on his finger, but he didn't receive this ring from anyone. The only other ring that was invisible and allowed him to disguise was given to him by Devourer.