Koschei the Deathless is a character from Slavic folklore, often depicted as a powerful and malevolent sorcerer. He is known for his immortality, which he achieves by hiding his soul in a series of objects, making him nearly impossible to kill. This clever trick allows him to evade death, leading to his reputation as a fearsome figure in various tales. In many stories, Koschei kidnaps beautiful maidens, including the beloved Princess Vasilisa, and battles heroic figures like Ivan Tsarevich. His adventures often involve quests to find and destroy his hidden soul, showcasing themes of bravery, cunning, and the struggle between good and evil.