Curse on the King and his descendents

In the year 1490, The trickster god, Idros, disquised himself as the then current  King of Amendia and had sexual relations with the then current Queen, from which her first born male child was born. The queen naturally thought she was havimg sex with her husband, the King. But when the child was born, it was only half human, the other half was monstruous. The King and Queen immediately knew they had been tricked.
The King had the child brought to the Lady of the Lake (see The Legend of The Lady of the Lake). He asked the Lady of the Lake to take the child but to do it no harm and to remove all knowledge of the child from history - so that it could never come back to haunt the royal family as it would have been the first born male child and might have entually become King (although unlikely as it was clearly a bastard). The Lady of the Lake agreed and she took the child, and its nursemaid from the King. Unbeknownst to the King, she had the child and the nursemade imprissoned in @Dark Holm, a prison in @Shadowfell. When Idros learned of this, he cursed the King with a waisting disease that would pass on through generations. Each King would eventually, in their early adulthood, begin to weaken and become sickly eventually leading to an agonizing and early death. The only way to reverse the curse was to get the child back from the Lady of the Lake.
The king that was thus cursed eventually died, and the last 20 years of his life were in agony because of the curse. Once his son, the current King, King Liam, assumed the throne, he too began to suffer from the curse and over time he became crippled and in great pain. He tried everything to reverse the curse - even going so far as to take on the service of a Brain Collector - which is a powerful creature of magic that "collects" brains and can use their knowledge and power as it own. Everything that was tried failed.
Eventually King Liam hired the services of The Right Fist to go to the Lady of the Lake and ask her to reverse the curse. She agreed, provided that they returned the bastard child to the Kingdom. This child is Gethos. Their exploits to free the child can be found in other parts of this site,