Balthazar's sword is an ancient and powerful weapon. It was given to him by a general he once served under; rather a strange action, given said general's dislike of the upstart Mangi warrior.
The sword's blade bursts into flames when drawn, giving it extra offensive power. It also defends its wielder from fires of all kinds. Due to the way its enchantment works, the sword cannot protect the wielder from its own flames, so Balthazar has to wear leather gloves to keep the sword from burning his hands.
Enchanted weapons like Balthazar's sword are rare among the forces of Heaven. Since angels are banned from casting magic, such weapons must either be older than the ban or captured from demons.