I Set Out in Search of Demons, Only to Return as Dust

When I was fifteen, my master divined that I would not live past twenty. He asked for a string of bells from somewhere else and told me they would ring nonstop when my destined opportunity appeared, and that this opportunity could change the curse that said I would die before turning twenty. But from the day I put them on, they never rang, until one day a monster appeared and the bells rang for the first time.