Din Djarin asks the Armorer to melt his spear in Beskar in order to make a very strong chain mail. In episode 6, The Stranger from the Desert, Luke allows Grogu to regain his memories.
Din Djarin is stopped by Ahsoka Tano, stating that Grogu is no longer an orphan, but a Padawan. They both understand and accept that he may never see Mando again, since he believes "a short moment for you is a lifetime for others."
The Mandalorian's last chapter is titled In the Name of Honor. Grogu made his decision, and he joins the Padawan, who defeated Fett and Shand's foes.