Knight-Commander Isold Hildegard

Isold is the 107th Knight-Commander of the Last Bastion, head of the White Cloaks.
Isold was once an ordinary Imperial Soldier, a scion of one of the great noble houses of Miercna.
But one day, while fighting a rebellion in The Eyrie, she found herself overcome by a holy light which left her blind. While wandering the world, blind and in rebel territory, she was sent several holy visions of the world being overcome by demons. On her recovery, she underwent a dramatic transformation in values; she no longer wished to fight sentient enemies of the empire. Instead, she felt called to a greater purpose: the protection of the world from demons.
Although what she did technically counted as going AWOL, she wasn't tried for desertion due to her family's pedigree. She was, instead, given a post at the Last Bastion, which was expected to kill her.
That was twenty years ago.