Your wish, Your soul

After the death of Zoro's childhood friend, he's suffered years from depression. But this suffering ends on the day he dies too. Before Zoro enters the gates of hell, he gets the opportunity to make a contract with this mysterious, blond demon: "I'll grant you your biggest wish ... if you grant me your soul!" Inspired by 'Kuroshitsuji,' AU, slight Zosan, Yaoi