Leaving the coast behind, Reiger didn't choose to teleport back to the Nameless Forest with Matthew. Instead, he slowly followed this visitor from Chaldea.
Because of her amnesia, the girl had even forgotten her own name, her mind was empty, and her delicate little face always bore a confused expression, so much so that she didn't even doubt Reiger or worry that this stranger might harm her. She just faithfully followed behind him.
If Reiger teleported to the Nameless Forest with Matthew right then, he was certain that the girl would only be more bewildered, perhaps even anxious.
Without understanding the current situation, not even knowing who she was, if he took Matthew to meet Altoria, to see Alberon, or to see her original companions, perhaps she wouldn't be able to handle so much information at once?
Therefore, Reiger decided to give Matthew some time to adjust.
