Domnall was a minor Fire Mage, too weak to do the larger battle magics, too slow to learn the art of stealth. Son of a tavern owner, he joined Fíngin’s army as one face among thousands of untrained, untalented fighters. They expected to die, those thousands, torn apart amid the battle magics, useful only as a living shield. They were there to buy time, to slow the demon hordes until the greater magics could be completed.
And that would have been their fate, had Domnall’s group not been ambushed whilst he was whipping up their final meals. If not for that attack, he never would have chucked a half-risen loaf of bread at the chittering hordes, discovering (to everyone’s amazement) that Demons were allergic to yeast.