The Witch of Prague & Khaled: A Tale of Arabia

In "The Witch of Prague" the main character is on a quest to find the woman he loves. When he gets to Prague, he falls under the spell of a witch.
In "Khaled: A Tale of Arabia" the main protagonist, Khaled, has no soul - but he is offered one chance: if his wife comes to love him, despite his lack of a soul, he will become fully human.