4. Giles, "Weight of the world" (song by Evanescence)

It was his duty as a Watcher to guide his Slayer, to teach her and train her, to increase her skills and her knowledge of the demonic realm and species. It was his duty to protect her and watch out for her, to strengthen her in body, mind, and soul, to prepare her for the brutality that she would experience in her short life. It was his duty to know her limitations and weaknesses and to transform them into strengths, to prepare her for anything and everything she might be faced with in the future.

As Buffy's Watcher, Giles was called to dedicate his life to her and her training, to put her and her responsibilities, and his responsibilities to her and to his job, above everything else. He was called to educate her and to raise her, in a sense, to provide support and encouragement, but also discipline and drive. He was called as Buffy's Watcher to bind up her injuries and hear her reports, to listen to her visions and provide her with the information she needed to battle and to guide her in how to use it, in what she should do with it and what she shouldn't. He was called to give her orders and to expect total obedience, and he was called to form such a relationship with her that she would unquestioningly give him such obedience and respect.

As Buffy's Watcher, it was Giles's duty to care for her, to hone her to be her very best and strongest… but it was also his duty to know that it was not her life or its preservation, but her responsibility, in the end, to the world, that mattered. It was his duty to know he would have to see her die.

It was not his duty, not part of his calling, to love Buffy, to regard her as he would his own child…but Giles did. And for that reason, the weight of the world seemed constantly upon his shoulders.