>The Magical Girl of Happiness dreamed for world peace and to bring happiness. This is also quoted by the Knight of Despair's Lobotomy Corporation Abnormality Story "The one who dreamed of a world of peace turned greedy and started devouring everything."
>"The first seed of desire originated from the pure yearning for happiness. The tiny seed grew larger and larger, hungering for more. Over time, the seed hardened and turned into a piece of shiny gem." Abnormality Page Intemperance
>"Happiness became obsession, obsession became greed, and the greed forever solidified to become a golden amber. The happiness in the beginning, still holding a smile, dwells inside." Abnormality Page Road to Happiness

This desire for happiness is what caused the Magical Girl of Happiness brought forth the desire for more and more until The Magical Girl of Happiness became the King of Greed.
Reading up on it, this only solidifies my belief that Rodya *is* KoG.
You have to engage in some wild mental gymnastics to justify KoDya.