In the Granston family, that was a secret that had been kept for two hundred years.
When Campbell's ancestors were fighting demons with blood outside Thunder City, Granston, the close comrade of the Duke, secretly established another layer of relationship with the enemy.
They secretly spared the Demon King, who was losing ground in the war, and secretly worshiped that lord, who was said to have a significant status in Hell.
After making an unspeakable deal, they exchanged insincere respect for the generosity of Hell, maintaining a mutually beneficial relationship with the Demon King.
Hell possessed many resources scarce on the earth's surface, such as precious magic materials, Demon Crystals, and most directly, gold.
And the Demon King of Thunder County also had things he needed, such as intelligence about the earth's surface, and battle achievements to report to the Demon City.
