Ruijerd's mission is to escort them home. He's done that. Rudy promised that he'd fix his reputation, and the Man-God has given them an answer to that now, so Rudy's role is done. Like Kraco said, heading back to the Demon Continent would be Ruijerd's next move. He also has other tribesmen to gather and spread news about. Maybe even get them to shave their head. (edit: what Ryll said)

Eris totally decided to leave before fucking Rudy. She didn't decide that afterwards. Like she said, she wanted Rudy to be family so she has someone to go back to after her journey is over. She's going to train while Rudy goes to the Magic Academy since that's the only way he'll advance. Somehow finding Sylphie and Zenith will fit into this picture.

I'm surprised that after all this time, that there are still people in tents. It's been months since the disaster. Those encampments make it seem like it's been 2 weeks. That said, I'm assuming that there's funding for action.