When Whistler has first shown him the tiny slip of a girl as her Watcher first approached her to tell her about her destiny, it had been easy for Angel to fancy himself in love with her. She was a golden goddess when he had been living in the dark for so long. She was sweet, innocent and pure. And he could tell from looking at her if she survived, she would be the key to his redemption. He didn't need to hear anymore of Whistler's pitch. Angel readily agreed to make his way to Sunnydale to wait for her arrival.
It had taken him almost a year to prepare for her. He had to reintroduce himself to human society, something that he had actively avoided twenty years or so. Having an apartment, clean clothes and pigs blood along with everything that goes with an apartment in a largely affluent little bedroom community was a shock at first. Especially since Whistler only hung around for a month or so. It was easy to keep true to the blonde girl whilst Whistler had been in town but when he left things became harder.
Angel still believed that the innocent girl he had seen in Los Angeles would be the key to his redemption but he just couldn't believe that he loved her. He didn't know a thing about her. Maybe it was lust but it couldn't be love. When he first spotted Darla hanging out amongst the crowd in the Bronze, it only made Angel question his intense feelings even more. How could he feel such a depth of emotion for someone whom he had never really met? He'd only ever spied her from afar since he had been wary about alerting her to his presence and winding up on the wrong end of her stake.
Something about it all made him question if he didn't have a type that he immediately fell for - whether it was love or more likely lust - at certain points in his life. Darla had been a turning point when he was slowly killing himself with gambling, drinking and whoring. She had turned him into a monster. And now when he was close to ending it all, Whistler had dangled a pretty blonde as a form of his redemption.
In the end, he decided to stay in Sunnydale, not for love but for the simple fact that the Slayer was going to need all of the help that she could get with the Master, Darla and the Harvest. He doubted that he loved her but Angel realized that she was his last chance. He couldn't just throw away his humanity once again.
* * *
She had surprised him.
From the rumours that were running rampant in Sunnydale's underground, he had been expecting an ill-prepared, untested Slayer who had only managed to survive the likes of Lothos because of luck rather than skill. Especially since all anyone could talk about was the fact that a Slayer had moved to town who wasn't interested in slaying.
He had heard the rumour often enough that he had thought that if it wasn't for the Master, the girl would be left alone. No one would want to be responsible for killing the Slayer that had no desire to do her job. As long as she was alive, Sunnydale could continue has it had. Still he heard rumours from the minions that chased after Darla that the Master had plans for the Slayer, retired or otherwise.
Angel decided that he needed to test her, to find out what he was working with. This was his chance for real redemption. And he needed to know the Slayer's mettle. Could he mould her into the warrior that she'd need to be? Or would he be better of waging his own war against Darla, the Master and their minions?
Yet she had surprised him. She might think of herself as retired or out of the game however he knew differently. It wouldn't take much to push her in the right direction if she continued with her reluctance.
He fought to ignore how pretty she was. How young she was. And most of all how innocent she looked. Yet he was powerless to resist her charms. He lost a piece of his heart to her that night. From that moment,. falling in love with her was a quick process. Angel knew who Buffy was now - she was more than just an innocent girl, a fragile slip of a mortal or a ruthless and strong Slayer. She was all of these things and when he was with her, he felt more like a man than he did a monster.
Yet he held himself back, cautious and careful because she was so young. The thought that he might harm her or hurt her just by his very nature horrified him. He wanted nothing more than to keep her safe from the monsters, including himself, that roamed Sunnydale.
In the end, he stopped trying to figure out his emotions. He just went with them. He loved Buffy. And that was all he needed to know.