Geography and Government
The Diamond Kingdom lies north of the Clover Kingdom. This country of mines and wasteland is poor in resources, so it focuses its efforts on building up its army and invading other countries to steal land and resources.
The Diamond military soldiers are called Mage Warriors 「魔導戦士 Madōsenshi」, who are in the service of the king, and similar to the Magic Knight captains of the Clover Kingdom who lead their own squads of mages, the Diamond Kingdom have the Eight Shining Generals who are tasked with leading their kingdom's armies and carrying out the orders of their monarch.
Mage Scholars perform human experiments to bolster the power of the Mage Warriors, by embedding mage stones into children with powerful magic and giving them additional abilities through reconstructive surgeries.
The Diamond Kingdom sends a team, led by Lotus Whomalt and Mars, to a dungeon that appears along the border with the Clover Kingdom. Although the team is defeated in battle by Magic Knights from the Golden Dawn and Black Bull squads, Lotus successfully escapes with his men and a large amount of treasure.
Months later, three Shining Generals lead an army to invade Kiten, a town along the border between the Clover and Diamond Kingdoms. After the Purple Orcas stationed there are defeated, ten Golden Dawns and four Black Bulls arrive to defeat the invading army. Ragus, Yagos, and most of the Mage Warriors are captured; however, Lotus manages to escape with Broccos and some Mage Warriors of his own. Upon returning to the Diamond Kingdom, Lotus reports on the battle to Morris.
Days later, the King sends an army, including Mars and Ladros, to invade the Witches' Forest and obtain the Witch Queen's secret to long life. Three defectors from the Diamond Kingdom organize the witches and help them defeat most of the army. Mars turns against Ladros after Ladros starts killing indiscriminately. It takes the combined effort of Mars, Fanzell Kruger, Fana and Salamander, and Asta to defeat Ladros. Afterward, Mars receives a bottle of Puppet Bloodflow from the Witch Queen and plans to use it in a plot to control the King himself and remake the Diamond Kingdom.
Months later, Zenon from the Spade Kingdom invades the Diamond Kingdom and single-handedly defeats one of their armies, including two of their Shining Generals. After six months, the Spade Kingdom has conquered most of the Diamond Kingdom.