The Lords of the Sword — Hugh Cook

SON OF THE DEMON--

That was what his former master had named young Drake Douay, when, maddened by illness, he founded the religion of the Flame and claimed Drake as his chief enemy. But Drake, fleeing his apprenticeship as a maker of swords, would only trade one danger for countless far more deadly ones. For in a world torn by endless wars of conquest, a land riven by wizard-powered trench of fire, an inexperienced youth would be hard-pressed to stay alive...