Fairy tale

It's a very distant time, back when there were kings and tsars. It was a time of wars and fears, but the Russian people coped with it and everything went on as usual. It was also a time of fairy tales, with the gloomy castle of Koschei the Deathless, Baba Yaga, werewolves, and various sorcerers.
Once upon a time there lived a king. The king had a daughter, Mila. She was beautiful, with red hair and green eyes. In short, she was just like her father, but such a bad temper, just wow! The king also had a son, Ivan—a kind boy, with golden hair and blue eyes, just like his mother, with a kind heart. They also had a childhood friend, Seryoga, a werewolf. When he was a child, he lost his parents, but he remained loyal to his friends; the forest was his home.
At some point, Mila was kidnapped by Koschei, and Vanya volunteered to make an "exchange" to save her. Koschei released Mila and took Ivan in exchange. Ivan agreed, but when Mila learned she had been brought low by the exchange, she decided to save her brother.
A day later, she and Seryoga went through the forest, through the fields, to Koschei the Deathless.