Lore[]
The sword-wife stood amid the burnt out ruin of her home. Everything and everyone that mattered to her was gone, and she was filled with fathomless grief... and hate. Hate was now all that compelled her.
She saw again the smile on his face as he gave the order. He was meant to be their protector, but he'd spat upon his vows. Hers was not the only family shattered by the oath-breaker.
The desire to go after him was strong. She wanted nothing more than to plant her sword in his chest and watch the life drain from his eyes... but she knew she would never be able to get close enough to him. He was guarded day and night, and she was but one warrior. She would never be able to fight her way through his battalion alone. Such a death would serve no purpose.
She took a shuddering breath, knowing there was no coming back.
A crude effigy of a man, formed of sticks and twine, lay upon a fire-blackened dresser. Its body was wrapped in a scrap of cloth torn from the cloak of the betrayer. She'd pried it from her husband's dead grasp. Alongside it was a hammer and three rusted nails.
She gathered everything up and moved to the threshold. The door itself was gone, smashed to splinters in the attack. Beyond, lit by moonlight, lay the empty, darkened fields.
Reaching up, the sword-wife pressed the stick-effigy to the hardwood lintel.
"I invoke thee, Lady of Vengeance", she said, her voice low, trembling with the depth of her fury. "From beyond the veil, hear my plea. Come forth. Let justice be done."
She readied her hammer and the first of the nails.
"I name my betrayer once", she said, and spoke his name aloud. As she did so, she placed the tip of the first nail to the chest of the stick-figure. With a single strike, she hammered it in deep, pinning it to the hardwood door frame.
The sword-wife shivered. The room had become markedly colder. Or had she imagined it?
"I name him twice", she said, and she did so, hammering the second nail alongside the first.
Her gaze dropped, and she jolted in shock. A dark figure stood out in the moonlit field, a hundred yards in the distance. It was utterly motionless. Breathing quicker, the sword-wife returned her attention to the unfinished task.
"I name him thrice", she said, speaking again the name of the murderer of her husband and children, before hammering home the final nail.
An ancient spirit of vengeance stood before her, filling the doorway, and the sword-wife staggered back, gasping involuntarily.
The otherworldly being was clad in archaic armor, her flesh translucent and glowing with spectral un-light. Black Mist coiled around her like a living shroud.
With a squeal of tortured metal, the spectral figure drew forth the blackened 
spear protruding from her breastplate - the ancient weapon that had ended her life.
She threw it to the ground before the sword-wife. No words were spoken; there was no need. The sword-wife knew what was being offered to her - vengeance - and knew its terrible cost: her soul.
The spirit watched on, her face impassive and her 
eyes burning with an unrelenting cold fury, as the sword-wife picked up the treacherous weapon.
"I pledge myself to vengeance", said the sword-wife, her voice quivering. She reversed the spear, aiming the tip inward, towards her heart. "I pledge it with my blood. I pledge it with my soul."
She paused. Her husband would have pleaded for her to turn away from this path. He would have begged her not to condemn her soul with this course of action. A moment of doubt gnawed at her. The undying specter watched on.
The sword-wife's eyes narrowed as she thought of her husband lying dead, cut down by swords and axes. She thought again of her children, sprawled upon the ground, and her resolve hardened like a cold stone in her heart. Her grip tightened upon the spear.
"Help me", she implored, her decision made. "Please, help me kill him."
She rammed the spear into her chest, driving it in deep.
The sword-wife's eyes widened and she dropped to her knees. She tried to speak, but only blood bubbled from her lips.
The ghostly apparition watched her die, her expression impassive.
As the last of the lifeblood ran from her body, the shade of the sword-wife climbed to her feet. She looked down at her insubstantial hands in wonder, then at her own corpse lying dead-eyed in a growing pool of blood upon the floor. The shade's expression hardened, and a ghostly sword appeared in her hand.
An ethereal tether, little more than a wisp of light, linked the newly formed shade to the avenging spirit she had summoned. Through their bond, the sword-wife saw her differently, glimpsing the noble warrior she had been in life: tall and proud, her armor gleaming. Her posture was confident, yet without arrogance; a born leader, a born soldier. This was a commander that the sword-wife would have willingly bled for.
Behind the spirit's anger, she sensed her empathy - recognition of their shared pain of betrayal.
"Your cause is our cause", said 
Kalista, the Spear of Vengeance. Her voice was grave cold. "We walk the path of vengeance as one, now."
The sword-wife nodded.
With that, the avenging spirit and the shade of the sword-wife stepped into the darkness and were gone.