Damon Salvatore experienced a significant character transformation in the popular CW show The Vampire Diaries after the first season, which played a crucial role in the show's long-lasting success. 

Based on L. J. Smith's book series, Kevin Williamson and Julie Plec developed The Vampire Diaries into a supernatural teen drama television series. The show premiered in 2009 and ended in 2017, spanning eight seasons and 171 episodes.

The story begins with Elena Gilbert, who is drawn into the supernatural world of Mystic Falls after the death of her parents. As the series progresses, a love triangle emerges between the two brothers and Elena.

By changing Damon's character after the first season, The Vampire Diaries effectively established the strained relationship between Damon and Stefan. Their shared history and romantic involvement with Katherine fueled their animosity towards each other. 

However, as the series progresses, Damon's transformation allows for the rebuilding of the brothers' relationship. In the series finale, Damon greets Stefan in the afterlife with the same words he said to him in the pilot episode, "Hello, brother."

 This final moment emphasizes the ongoing focus of the show and proves that the success of The Vampire Diaries relied on the loving relationship between Damon and Stefan.