In my fantasy novel Eliana, there is a character that I've got planned out, except how he got into the situation he's in. I'd better explain the plot. King Hinrak was once a loved and benevolent king. Somehow, he became evil and twisted. His power was great, and he somehow inherited very dark powers and can turn into a dragon. I have absolutely no idea how to make him inherit these draconic and demonic powers, and what made him so evil all of a sudden?