Updated; beta-ed by Utsu.
This is my first story in English. So, you must know before reading anything of this that English is not my native language. I'm French, and I do mistakes. I really hope that it will be okay and that you will enjoy this Kelsier as much as I did!

A promise of betrayal

Kelsier stood on the balcony, the mist curling around him, thick and cold against his skin. He didn't bother to wear his mistcloak, dressed only in his casual skaa pants. The stone was cold beneath his barefeet and his partial nudity made him shiver. He didn't care.

He didn't use Allomancy either. He liked the way he couldn't see through the mist, the way he felt when he was alone out there in his element. Waiting with his mistakes and the curling mist to remind him of what he'd done. Not only to Mare. Not only to Marsh. Nor about that which he had done in the past but more about what he intended to do.

His plan was insane. He knew it more than any other in the crew. Who was he to use them, to urge mere thieves to overthrow the Lord Ruler? Why did people believe in him so much? Those questions haunted him every night, as did the memories of the Pits. He wondered if he would be able to do it in the end, to use the eleventh metal to kill Him. Or would he become a new martyr, en embodiment of hope to the Skaa people and lead them to rebellion despite their terror? He wondered if his friends would forgive him. Still, he was determined.

Mist pushed him to face reality. Through it, he was able to discern his death waiting for him. He could see the anger in Vin's eyes, the sorrow, the mourning. He felt all her hatred and passion as if he were using Allomancy. He was a Mistborn, after all. Maybe the mist really wanted him to foresee these things to convince him that all his planning wasn't in vain.

He sighed and started making his way back to the mansion.

Walking into the deserted corridor, he stopped in front of Vin's door. Poor child, he thought. She was Mistborn too – a talented one, at that – and she wasn't ready to lose everything. Kelsier's crew was probably the first thing she had ever really loved. She'd never had friends before, only a brother that had protected her, only to later betrayed her. Now, she was constantly paranoid, often alone and extremely stubborn. At least, she was doing better since she having started learning Allomancy with him and the other members of the crew. He hoped that she would live longer than he did, in a world better than this. He wished Mare could get to know her; she'd always wanted a daughter. He had to admit that he felt something for the girl. Not in a romantic way, of course – that would be ridiculous – but something more like fatherhood. He liked teaching her new tricks, he felt happy and proud when she managed to do something new and he felt bad when he lied to her or when she glanced at him with that particular suspicious look. Amongst them all, she was the one who understood him the most, despite having only known him for a few months.

He couldn't resist the temptation to enter her room. Slowly, he pushed the door open before walking in, careful to soften his footsteps so as not to wake the sleeping Mistborn. He could imagine the look of disapproval Sazed would have given him if he'd caught him sneaking into a lady's room at this hour in the morning. However, the risk of his attendant lecturing him did not in any way prevent him from doing as he wished.

The thought made him smile one of his characteristic smirks. He wanted his crew to remember, after he passed on, how important smiling was. And what friendship was too. He sat on the floor, elbows against his chest as he watched Vin sleep, curled up in her bed. He kept smiling at the sight of her, enjoying the feelings of warmth she evoked in him. It was weird for him to have someone like daughter, to acknowledge. Her as he did.

As though suddenly aware that she was not alone in the room, Vin opened her eyes, jolting at his presence next to her bed. She immediately began burning metals, ready to protect herself. His smile widened as she frowned. "Kelsier?" She whispered into the dark of the room.

"Go back to sleep, Vin. I was just passing by." He stood up and felt drained. Maybe he should get some sleep too.

"Kelsier, is something wrong?" Said Vin a little louder, her voice – quite deep for a woman – still hoarse.

He shook his head knowing that she would be able to see him in the dark as she continued to flare tin. "Absolutely nothing," He answered in a low voice. "I'm sorry I woke you up."

He restricted the urge to pat her on the head and left the room. Vin stayed alone in the dark, wondering what was wrong with him and what he was hiding beyond his strange behavior. On the other side of the door, on his way back to his own room, Kelsier felt the guilt weighing heavy on his heart.

I am sorry, child, he thought. One day, I'll betray you too. I'll leave you behind with all the responsibilities and I only hope that you will be able to find it in your heart to forgive me. Thankfully, he wasn't a father after all. Because what kind of father would abandon his children as he was about to do to his crew?

The thought had a bitter taste.