In Leigh Bardugo’s books, Sturmhond is an alias held by Nikolai Lantsov, the highly competent second son of the King of Ravka. He doesn’t have a direct line to the throne; it is rumored that Nikolai is a bastard, the son of Queen Tatiana Lantsov and a Fjerdan shipping magnate. Regardless of what his true parentage might be, Nikolai has no intention of sitting around while his country suffers. So, he safeguards its borders and uses a commoner’s identity to free himself from the eyes and ears of politics, so he may win the heart of his people.
Under the disguise of Sturmhond, Nikolai controls the sea to defend his homeland as best as he can. He forges alliances, and helps anyone who needs it, and brings Alina back where she belongs. He’s undoubtedly a fan-favorite character in the books who spits many whip-smart lines, gets what he wants, and does consistent good.