Defeat 10 Snow Elphas and 10 Ancient Elphas near Skadi's Eye. Then talk to Milton Oustin at Skadi's Guard Post. This quest can only be cleared once a day.
Milton Austin: Hoy! Aitan, my hero~~ NakanoAzusa: Hey stop that... HiiragiKagami: You're kind of annoying... Milton Austin: Because of the Nail of Freezing...? NakanoAzusa: Yep, got it in one. Milton Austin: Yes! I finally helped you, master NakanoAzusa. NakanoAzusa: Yeah... Look- Milton Austin: For a long time, people used Nails of Freezing to freeze and Milton Austin: Nails of Thawing to manipulate magical items. This is Milton Austin: the best place to make the Nail of Freezing. HiiragiKagami: Just tell me what you need! Milton Austin: Alright~ a Severe Ice Stone is needed to make Nail of Freezing. Milton Austin: But I also need to follow my commander's orders. NakanoAzusa: So? Milton Austin: I've got orders to defeat Elphas. Can you do it for me? Milton Austin: I will make you a Nail of Freezing while you're at it. NakanoAzusa: Hm... That's easy enough. Alright. Milton Austin: However, I can only make one per day. HiiragiKagami: What does that mean!?! Milton Austin: I'm glad to work with you every day until you collect Milton Austin: enough Nails. You make me so happy! NakanoAzusa: It's worth it...It's worth it....It's worth the headaches...
Reminder Dialog
Milton Austin: I will give it my full attention when crafting it.