A/N: Bit of an AU where Lucina kills Robin in chapter 13. Robin is Lucina's mother to add a little more to the story. I wrote this earlier and would've posted it a week ago, but my computer crashed and I had been at a summer camp last week.

"Father, no!"

Everything happened in a matter of seconds. The haste to block the Risen's blow. The undead soldier's eyes affixed lifelessly at its target: her father. She fussed over him in a matter that could only match her mother's, forcing tears to go unshed. The exalted stared with his mouth agape. "You called me 'father'." The man's expression was genuine confusion.
Lucina mentally kicked herself. "Erm...May we speak in private?" She received a nod in response.

She wrapped her arms around her father as if in fear that he would fade away if let go. Tears spilled, soaking his armor as well as her own.

"...Chrom?" A feminine voice spoke, and Lucina felt an icy hand grip her heart.

Robin shook her head, both in disbelief and horror. Lucina's hand rested on Falchion, the only shard of her tattered world. Lucina's thoughts were broken by Robin's quiet voice. "...Are you really my daughter?" The snowy haired woman was hesitant. Lucina only gave a short nod.
"She has the blood of the exalt, no doubt. The brand in her left eye proves it." Chrom chuckled. Lucina took a few steps fowards, as did Robin. A glimpse of the purple brand engraved into her mother's hand made Lucina's breath hitch. It was Grima's mark. Memories of her future darted in and out of her mind. Her heart raced.
Her mother was slowly but surely being transformed into the same fell dragon that destroyed her world. The joy in Robin's eyes was genuine, but Lucina's mind was blank with fear. The snowy haired woman's lips began to form Lucina's name as the princess's sword stabbed through her stomach.

Robin gasped as her brown eyes widened. She stared down at Falchion impaling her, and then to Lucina. Tears once again stained her face as she met the dying eyes of her mother.
"I-I'M SO SORRY!" Lucina shouted. Robin reached out and wiped away her daughter's tears, a weak smile plastered on her face. She fell with a thud as Lucina yanked Falchion out of her mother and threw it to the ground. Chrom yelled his wife's name and Lissa scrambled to her dying side. Lucina glared at her hands, now stained with the blood of Ylisse's queen and her mother.

Lucina sighed as she studied the maps before her, readjusting the worn cloak of her mother. She would've thanked Naga she wasn't killed on the spot, but Naga would not have wanted to be thanked by a murderer. Lucina secluded herself from the other shepherds, whom had given her glares or no attention whatsoever. Lucina was treated as a prisoner by most, including herself.
"Milord, we're ready to retrieve the tear." Lucina pulled the cloak's hood over her face.
"Thank you, Lucina." He replied. Lucina could hear the pain in his voice and the guilt too much to bear. She had been cutting down the Risen as quickly as possible, until a young man had tackled her.
"Mother! It's you! I've finally found..." He was cut short when he observed Lucina's features. "You're... you're not..." Lucina gaze at his unruly royal blue hair and Naga's brand etched into his hand made her heart nearly stop.

The Shepherds had retrieved Naga's tear and were in high spirits. Morgan was immediately welcomed with open arms as Chrom's son. Lucina felt her heart shatter as he glared with bloodshot eyes.

He was mourning Robin openly, and resented Lucina whole-heartedly. Not like she blamed him. She hated herself,too.

In the few hours of the night, Lucina lay on her bed roll, glancing at the tiara she had once worn with pride. The golden wear was tossed to the corner of the tent. Not like she needed it.
She wasn't the princess nor exalt. Not anymore, at least. She was a murderer with a broken soul. With a deep, low sigh, she gripped the hilt of her sword and a handful of her blue locks.
Within only seconds, her hair as strewn on the floor, slipped on the mask she knew too well, and became the Hero-king once more.
"No one would miss someone as selfish as me." She whispered in a monotone voice and fled into the night, leaving the parallel Falchion and tiara behind. No longer would she continue to live by the name Lucina, but by Marth once more.

"So what happened to the princess?" A red headed girl asked, clutching her pegasus toy.
"Well, after sending Grima into its sleep once more, the exalt searched far and wide for the princess. She had disappeared without a trace. If not for his family, he would have been lost to grief."
Marth took a shaky breath before continuing. "He raise his child with the love of both his wife and himself. Prince Morgan had grown into a kind young man. Eventually the princess was just a memory."
Silence.
Marth felt a tug on her cape. "Aw! But that's not a heroic ending!" A boy with wild dark brown hair and a brand to match her own cried. Several other children agreed. Marth only chuckled and looked from child to child, her eyes resting on a girl with the same fair blue locks and a tiara placed pridefully on her hand.

"I'm sorry, young man. But not every story can have a heroic ending."