Disclaimer: I do not own Vampire Knight
Kaname was a pureblood. Yuuki was a human and Zero was going to be a level E. As much as Kaname hated Zero, he couldn't let the kid die. Yuuki, his beloved, his little sweet and delicious human, was all he cared about in the world. That being said, any harm, any pain that might befall her, he would do his utmost to prevent. And, being a pureblood meant there was a lot he could do. Only thing was, being a pureblood meant he hadn't been able to watch her grow up, he'd left her side and she'd become attached to Zero. So yes, he loathed the young vampire with every fiber of his being. He could not, however, act upon this, as much as his powers willed him to, because then Yuuki would be sad. Kaname had gone around in circles with this, he could let Zero go E, and then when he was killed he could comfort Yuuki but Zero was surprisingly resilient, not resorting to being a vampire for years, and then, not falling to level E. Kaname knew the only thing keeping Zero from falling to E was Yuuki, his love for her, and her willing blood sacrifices to him. It made him sick and he had to make a conscious and struggling effort to keep his temper in check. However, he loved Yuuki too much to let her suffer through the death of one of her best friends, despite how much he loathed him. So, he let Zero drink his blood, much as Yuuki had done for Zero, to save him. But one day, when Kaname was stronger, he would be able to suffer through her tears, he would kill Zero. And then Yuuki would be his. But for now, he would wait, in this chess game, Zero was merely a pawn, protecting his queen and this game was only beginning.