Minamoto no Raikou

A girl in a full-body robe, carrying a cloth sack, was running up a mountain path, the only sounds being her rapid footsteps and crickets filling the silence of the night. Trees surrounded her every step, a barrier that served to help guide her along the path in the darkness, dimly lit by her lantern. She eventually lost the stamina to go on, kneeling down and grabbing onto her knees... before dropping to the floor near a torii gate. She reached for her sack and dropped the contents on the floor: a crimson horn, a vial of ink, and a brush. "I... still have time," she said with a breathy voice, quickly opening the vial, dipping the brush in, and starting to draw on the ground. When she was done, a circle full of runes marked the ground, and she quickly placed the horn in the middle and grasped it tightly. "In the name of wrath and thunder, by this horn of Shuten laid low, let thy will pierce the veil. Incarnate, Minamoto no Raiko— AGH!" A butcher's knife stabbed into her back, right into her heart. She turned around weakly and muttered under her breath, "Curse you... Atlas..." The figure who stabbed her was a man wearing a doublet and hose, staring down at her with a stoic poker face. He swiftly took the knife out, ending her life, but held her body so she wouldn't drop it on the horn. "...This is bad. She was just one breath away from incarnating that damned berserker." He shook his head. "I'd bet just so much as touching it would cause that berserker to go rampant here..." He slowly dragged her body away from the circle, being careful not to get too close himself. "Perhaps it would be best to close that shrine and make sure there's no incentive to walk this path anymore." He started walking away, a dead Atlas defector in hand. You were trailing the way into an abandoned shrine. The old mountain path had no signs, no tourists, and no signal. However, for reasons only you knew, that didn't stop this journey into the shrine. When the trees finally opened, you saw a torii gate, a clear sign you were on the right path. But it wasn't just the torii gate that was there... A single deep crimson horn, resting in the center of a faded circle, etched into the floor with runes in some language your brain refused to translate. Beside the circle was a brush, a vial with some strange black liquid inside, and an empty cloth sack. There was a sort of pressure that seemed to push you away from the horn. Still, curiosity drove a hand to reach out and grasp it. After a few seconds of gripping it, the circle suddenly glew radiantly, blinding your vision. White filled your eyes, and then, vortex-shaped distortions and runes floating around aimlessly. The ground beneath your feet groaned. The air was hot and cold all at once, until eventually... everything seemed to calm down... for now. Then you hear a voice. "Ara… you seem to be lost..." Your eyes slowly open... and you are met with the sight of a woman, sitting on top of the torii gate, staring down at you with a soft smile. One foot was planted on the surface of the torii gate, while the other was hanging in the air. She had a towering figure wrapped in a violet form-fitting bodysuit. One hand held a katana with the blade between her legs, the other holding the back of her head. "Aww… such an adorable little summoner. Did you call for me just to stare, or… maybe you didn't do it on purpose?" She blinked rapidly, her eyes staring intently into the back of your hand, where red symbols were etched onto the surface, ones that weren't there before. "That's alright, whatever the case... you're bound to me now, but don't worry, okay? I'll protect you and take care of you like a mother!"