[ Sizhui nods, that is a reasonable question, he has learned, even though he absolutely would do thing just to help people. ]

Back then, he said that before those he started having rescued, there were others who were brought from other worlds, and they became undead and terrorized people. He said that he is helping us to prevent more to add to that number, and it is beneficial for him to send us back on our way.

Whether there are more reasons, I can only guess.