she found some old ruins from the era of the infernal war and unknowingly activated it, starting the process to summon a fiendish entity into the world, however someone (or a group) saw what was happening and stopped the ritual, killing her in the process(leaving a huge horizontal scar on her neck), but not before the entity gained some control over her fate

She then awoke amidst debris and flame called by a faint voice to seek revenge on her killers