Dragons are probably the most powerful magical creatures of all, and have the greatest magical knowledge and ability. They can pass the extremely effective spells they know to humans with their mind. Kilgharrah showed Merlin two enchantments, one to trap Cornelius Sigan's soul back in his jewel (who was the most powerful sorcerer of the Old Religion ever to live prior to Merlin) (The Curse of Cornelius Sigan), and then a healing spell to cure Morgana of her fatal cranium wound (The Crystal Cave). Aithusa was also able to heal a dying Morgana, simply by breathing on her (The Sword in the Stone).