Something in the way he fought, so recklessly even for him, unsettled her. In any fight the more likely your opponent is to make mistakes, the better chance you have at defeating said opponent, and this instance was no different from that. She realized, suddenly, that she was the one who initiated the fight, and that he wasn't trying to break out of his defensive.
Looking down at him, kneeling on the ground, her sabre hovering just below his chin as he looked up at her, eyes locked with hers, she didn't feel the relief of a battle won. Kylo Ren might have lost, but she didn't win.
And there was something in his eyes… In any other situation she would have ignored it, but not when she saw how he fought just then, and how once again she was the one without a scratch on her and he still bore the mark of his defeat on Starkiller Base.
His lips quivered as her sabre faltered at his neck, eyes flashing with rage.
'Do it!' He yelled, and Rey could barely believe her eyes. A single tear rolled down his cheek, but he looked on with the same determination, the same anger as before, as if it did not mean a thing. 'Take your revenge! What are you waiting for?'
She pulled back as he moved himself forward. The blue light of her sabre shrank back into the hilt.
'No,' she said softly, but just loud enough for him to hear. 'I'm not a killer.'
His look hardened, burning rage turned ice cold, then slowly melted away to be replaced with something akin to resignation.
'If you don't do it,' he said, his voice surprisingly gentle, eyes cast down on the ground, 'Someone else surely will. I'm a dead man already.' He looked up at her again, but his look was unreadable.
No matter what he wanted, Kylo Ren didn't deserve to die, and if he deserved worse or better was not up to Rey to judge.
So that's it. I don't intend to continue this, but I might submit a different one that could be considered as vaguely connected. Please share your thoughts on this story in the reviews, or if there's anything you'd like to see me write in the future, feel free to message me, I don't bite.