is the "good" brother. He is a 162-year-old vampire who refuses to drink human blood, subsisting instead on animal blood ("bunny eater," as his brother calls him). He returns to Mystic Falls not just for a fresh start, but because he is drawn to Elena, who bears an uncanny resemblance to a vampire from his past, Katherine Pierce.

These rules are not just lore; they are plot devices used constantly in Season 1. Vervain is the reason Elena can defy Damon. Invitation rules create countless tense cliffhangers.