Golden Prince Diamond King

Orrin of Zigag (a very naughty prince) is about to meet his match as his father is marrying him off to the widower King of Doriar, who had requested Orrin's twin brother hand. Their father thinks Joran of Doriar will have no issue with the twin exchange since technically they have the same body.
Nevertheless, things aren't that easy because the Diamond King of Doriar has heard of Orrin's exploits. Perhaps, the blond prince doesn't need a firm hand but a rough one, and (since Joran wants to settle an alliance with one of the Five Ocean Kingdoms) he is up for the challenge.
Who will be tamed in the end, the Golden Prince or the Diamond King?
This story comes from the NIGHTJAR universe (an ancient Greece/fantasy retell).
Also a bonus story from another far away realm. Adults Only.