Merlin in "the Sword Excalibur" placed Excalibur into an anvil atop a stone, saying that only the true King of Britain would have the power to pull it free. He advised Arthur how to officially become the King. It's a positive advice.
On the other hand, the pilgrim Shadow in "Eldorado" knew that the gallant knight was tired of the finding the land of Eldorado, he advised the knight to stop his journey. It's a negative advice.
