1. To fulfill Arthurian Legend: The death of Arthur Pendragon is a central element of the Arthurian legend. Though the specifics vary across different versions, Arthur's death is almost always a part of the story. The show's creators likely wanted to stay true to this fundamental aspect of the myth, even while taking creative liberties with other elements.
2. To create dramatic impact: Arthur's death is a powerful and tragic event, capable of eliciting a wide range of emotions from the audience. It serves as a turning point in the story, marking the end of an era and the beginning of a new one. The show uses this death to drive home the consequences of Arthur's choices and the weight of his legacy.
3. To explore themes of sacrifice and destiny: Arthur's death is ultimately a sacrifice for the good of his people. He chooses to die rather than let his reign of peace and prosperity be shattered by Morgana's darkness. This reinforces the show's themes of destiny and the importance of fulfilling one's purpose, even at great personal cost.
4. To create closure: The show's final season sees Merlin and Arthur grappling with the weight of their destiny. Arthur's death provides a sense of closure to their individual journeys and highlights the emotional impact of their sacrifices.
5. To offer a different interpretation of the legend: The show's creators intentionally took liberties with the traditional Arthurian story. They didn't want to simply rehash the classic tale, but instead, offered a new perspective on Arthur's life and death.
It's important to note that while some viewers found Arthur's death a satisfying conclusion, others were disappointed by the departure from the traditional legend. Ultimately, the writers' intention was to use Arthur's death as a pivotal moment that would propel the story forward and explore the complexity of their characters' choices and sacrifices.