The first time they met, she glared at him with a fiery defiance. She couldn't see him, not really, she just saw the monster he showed to the world. All she saw was the creature in a mask.
When she woke in the restraints, she saw past the facade, she saw straight into his mind and revealed his secrets. And yet, he didn't look at her with hatred, only shock.
She watched him kill his father, from the railing far above. She could do nothing as her blood boiled and the sky darkened around them. They had to leave, she knew, they had to get off the planet. As she turned, his eyes met hers. They were filled with shock and pain, no anger. But when his eyes moved to Finn, they filled with the pure anger he never had while gazing at her.
They met again in the frozen forest, the cold seeping into the bowcaster wound in his side. He was fueled by rage while fighting the traitor, the one who abandoned his brothers in the First Order. But as the lightsaber flew past him and he found the girl facing him down, he found all anger draining out of him, leaving only the pain, and the suffocating guilt he would probably never be free of. He asked her to join him, so he could teach her. In response, she just caused more pain. But pain is good. Pain distracted him from the thought of his father. And yet.. Even as he lay on the ground, a deep gash slashed across his face, the blood getting mixed with snow and freezing, unable to move, the pain almost faded away, and he prayed for her to end it all, so he wouldn't have to feel this conflict. But then the moment passed, the ground split between them, the Force keeping him alive, for now.
They saw each other again mere days later, but not in person. She woke with an odd feeling, like someone was watching her, and yet no one was there. She looked around until she saw him, sitting with the scar she gave him slashed across his face, and he just looked at her in shock. Even as she shot the wall of her hut, and he tried to mind-trick her, and commented on the impossibility of this situation, his eyes had nothing but surprise. No hatred, no anger.
The rain fell around both of them when they met again, the ocean spray splashing on her face as he looked at her, the anger in her eyes as she called him a monster yet again.
When he was vulnerable, she looked away and demanded answers. When she had no answers, she came to him once again.
She faced down his master, the master who he stopped obeying the instant he hurt her. The resolve sensed was resolve to never be trodden on again. The anger was not towards her, no, never towards her. It was to the one who hurt her, the one who would die at the hand of he who was no longer fully in darkness, and perhaps never had been. He ignited the blade, and his master fell apart, while the girl he cherished fell at his feet. He stared at her, she stared at him, and wordlessly, they understood.
Back to back, they fought their way to freedom. Back to back, they protected one another. Back to back, they each grew closer to the grey.
When he asked her to join him, to let everything die and start over, for a second she almost agreed. A part of her tore itself apart as she pulled on the lightsaber, rejecting his offer.
They saw each other again, countless times. But only twice again in person. The first, when she was back on her home planet, retrieving a crystal she had scavenged years ago and hadn't been able to get rid of. He appeared behind her, briefly explaining how he was going to end the regime he had worked for seven years to build. And kissing her goodbye.
The final time they met, he was lying on the sleek floors of a First Order station, a small outpost that should not have had three Knights of Ren guarding it. But, it did, and the Resistance couldn't have anticipated it. But he was there, and he took down the guards, he was to issue a cease fire to the entire army from that very outpost. But a Resistance soldier, one she didn't know, had panicked at the sight of the Supreme Leader of the enemy, had fired off a single shot to the back. She didn't see it coming.
He let it happen.
With his dying breath, he projected into her mind the things he had seen, everything that he had done that would prevent him from ever being accepted or even tolerated by the Resistance.
Moments later, Leia rushed into the room, and fell upon her knees beside the body of her son, and embraced the woman he had loved with the warm, tearful hug she had been saving for him.