The Dark Lord, Mael was in fact, not originally a Dark Lord. But he was ensnared by the Dark Curse. Truth is, the Dark Lord is just an ordinary human named Mael with absolutely nothing going for him. He worked tirelessly in a Vitality Banana factory. Slaving away until he eventually passed. One day, he found a box. For no particular reason other than sheer curiousity, he opened the box and the Dark Curse flew out. It freaked Mael out so much he tried to run away. But before he could, the Dark Curse possessed Mael. It transformed him into the Dark Lord you know now. Mael then lost his humanity - all the light in his soul, and turned into a malformed puppet of pure darkness for the wisp to take control to exact it's reign of terror.
Throughout Mael's time as the Dark Lord, he experimented greatly with the powers of Darkness in his Castle in Karkaton. In his attempts to create monsters for his army, he experimented with humans. One of them being a girl named Sherry, who was infused with an Imp at the age of 7. Some died from the horrible experiments, but Sherry was the only girl who survived everything. The darkness overtook her soul yet she was the only one who lived. Despite this, Mael thought the whole idea was a failure, and he threw Sherry out as he assumed she'd eventually die. But it was not long after that he discovered using souls could fuel his army. Between monsters and just regular creatures not tied to the darkness, they were all the same to him. All the same to exploit and use to gain members for his army.
He eventually found Manor Macabre, of which the last vampire family - the final presence of darkness remained. He exchanged a Bat Charm for Alessica, the family's middle child, who had been claimed to be a prodigy in vampiric powers. The Dark Lord exploited her to help him produce monsters for his army. Not knowing the chaos that they would cause later.