Enchantment by Nimue (or Viviane):
Merlin’s downfall comes through his love for Nimue, the Lady of the Lake, or Viviane in some texts. Teaching her magic, he is betrayed when she uses his own spells to imprison him in a cave, tower, or enchanted forest (accounts vary). In Malory, he is trapped under a stone; in the Vulgate Merlin, he is encased in an invisible prison. This marks his exit from the active narrative.
Continued Influence Post-Imprisonment:
Even after his entrapment, Merlin’s influence persists through his prophecies and the legacy of his guidance. In some tales, he communicates with Arthur or other knights through visions or magical means, ensuring his wisdom endures.
Merlin’s fate varies: some sources suggest he remains eternally imprisoned, alive but removed from the world; others imply a symbolic death or retreat to a mystical realm like Avalon. In Welsh tradition (e.g., as Myrddin Wyllt), he becomes a wild prophet living in the forest, driven mad by war’s horrors.