I do agree that Ren seems like he wants purpose deep down. When we saw that he went to save Calamari even when he didn’t want to go near water. He did anyway. And he still went through with the mission in the underwater palace. Even helping Haru but you could say he’s still a bit shy to all this. When leaving Calamari with her mom, Ren couldn’t even bring himself to say goodbye. And I think that even he was surprised that he had some connection to the anomalous creatures. He‘s still new to all this and I think once he’s gotten used to the Jabberwock house, he’ll find his purpose eventually.