Caligo

Two sisters, born three thousand years ago, were given powers that made them immortal. Although twins, they couldn't be more divergent.
One was given power over light. The other over darkness.
Lucis, the blessed one, adorned by humans, was thought to be the goddess.
But Caligo, who was cursed, lived the life in solitude, and was considered a demon.
This is the story of a dark sister.
This is the story of Caligo.

''Both girls opened their eyes, and in that moment clouds dispersed and the moon shined brighter than ever. One had soft amber eyes, the other unnatural blue ones. 'Lucis, the light' said the druid, pointing at the first girl, 'Caligo, the darkness' he pointed at the other one, whose piercing blue gaze examined her surroundings.
'One will be our savior, the other our doom.' The old man said, he and his wife, the healer, turned to exit the hut. 'Which one?' The chief asked. 'The one with the black heart.' answered the druid''