Welcome back to Humor Nation. He started off as a villain but soon became a fan favorite. He is one of the two primary male protagonists of the show. Damon was turned into a vampire by Katherine Pierce, he returns to Mystic Falls and confronts his brother Stefan Salvatore after 15 years. He shared a bittersweet relationship with his brother Stefan, even though the brothers had a violent relationship, but the brothers cared for each other. Damon wasn’t a cold monster always. During the 1950s, he was captured by the Augustine society who tortured him. During his time in captivity, he met another prisoner named Enzo and became best friends with him. But when their plan of escaping failed and he believed Enzo ‘died’ because of him. He decided to turn off his humanity in order to suppress his sadness and guilt.
In the pilot episode, we see him returning him to the town of Mystic Falls. His purpose of coming back was to free Katherine Pierce, his sire, from the tomb in which she was never in. Damon loved Katherine for 146 years, but after realizing that Katherine never loved him, his feelings for her start fading and he starts developing a love for Elena Gilbert. Before becoming a vampire, he was a free-spirited guy who didn’t care what people thought of him. His dark side came into play when he fell in love with the vampire Katherine.