In the end, Castilian hugged Durin, "My real name is Dunor, this name was given to me by my human mentor. He passed away, so I've always used this name, hoping to remember him."
"At least you still remember him, right? I understand." Explaining this, Durin took another look at the dwarf before him and then smiled as he hugged him, "I only did a tiny thing, your gratitude is too much for me."
"Don't be modest, my little sir. Do you know how much your pickaxe shocked the Dwarf Race? I was originally the youngest son here in the Human World to slack off and wait for death, but now, my whole family hopes I can learn something. I have to go now, I still have to go for tutoring." Castilian said with a wry smile, bid farewell to Durin, and then left with his brothers — it's said they all had to go back for tutoring.