This was written in response for notgoodenoughforodin's (on Tumblr) request for a nightmare strong enough to break Loki. Please don't hate me.
Loki rolled over in bed and smiled at the form of his sleeping wife beside him, her hand resting on the swell of her pregnant belly. They were going to have a child, and Loki couldn't be happier. After years of being alone and craving affection, longing after a family he thought he would never have, he was in Valhalla. Loki finally had someone in his life, not only to receive affection from, but to give it to. And soon, he'd have one more, tiny, person in his life to love and cherish. Loki slowly drifted off to sleep, an arm around the love of his life and dreams of the future running through his mind.
But his dreams were not going to stay pleasant and hope filled. Slowly, memories from his past seeped into his dreams, building up to full nightmare strength. He thrashed in his sleep, trying to escape the clutching hands in his dreams, waking his wife up. She clasped his shoulders and gently tried to shake him awake, saying his name over and over. But in Loki's mind it was Thanos that had a hold of him. He struggled harder and his scepter materialized in his hand. While he thought he was stabbing Thanos with it, that was not what was happening. Over and over again Loki stabbed his beloved wife in his sleep, the tip of his scepter finding its mark deep within her body. Her cries and screams mingling with Thanos' in his mind.
Later, Loki woke up, and he felt his wife's arm draped over his chest, she felt cold. He reached to gather the blanket up around them and his hand touched something wet, a panicked thought went through his head that his wife's water had broken. He called out her name to rouse her as he waved a hand to turn the lights on. In the light he noticed that his hand was covered in blood, he looked to his wife for an answer and that was when he saw her mutilated body.
He tried to wake her as he took a closer look, her face was a mask of pain, she was covered in blood and a coppery tang filled the air. His eyes traveled down her body, trying to understand what had happened. He paused when he saw her torn belly, it looked like she'd been ripped open. He couldn't look away and Loki was able to see traces of his unborn daughter amongst her mother's torn and bloody flesh.
Shaking, he got up from he bed to call for the Midgardian authorities. As he walked to the phone, he stepped on something cool, metallic and cylindrical. He looked down and saw his scepter. Suddenly, reality hit him, he had done this, he had murdered the one woman he ever loved...he, Loki, had murdered his unborn daughter. He moved back to the bed and caressed his wife's cold face, closing her eyes. He reached out to touch the tiny hand of his daughter, weeping over the damage he'd done. With an unholy cry, Loki disappeared into the night.