But it's a happy icon! Well, at least to anyone who doesn't know the canon and know that that expression is only used during the two saddest scenes with Leonhardt.

Still, you are right. Joshua's wish to not go home will lead to an argument, even if it is still pretty abnormal for someone who is dead in their world to want to go back. Joshua at least has little reason to worry about Leonhardt in Luceti now though, because he's not going to try and get himself killed. He understands now if he wants death, his best avenue is to find a way home, so he's keeping himself busy with finding out as much as he can about Luceti. Still not completely healthy, but at least a vast improvement.