Basically a song about Gakupo but ITS FREAKY...
The story takes place in the region of Asmodean in Beelzenia, as Duke Sateriasis Venomania greets another woman who approaches his mansion. He explains how he made a deal with a demon to have an irresistible charisma to women; as a result, women flock to his mansion's basement to create a harem for him. The Duke burns all his old portraits, revealing how he had been mocked and taunted in childhood for his appearance. He kisses another girl in his harem, Gumina Glassred, who had been his childhood friend but also made a fool out of him. He continues to build his harem and women begin disappearing from all over the land.
One day the duke greets a new woman entering his mansion, approaching "her" to dance; as he does so, however, the "woman" stabs him with a knife, revealing himself to be a man who had tracked down his lost love to the Venomania's home. Due to the injury and the knife's poison, the duke collapses and his spell breaks; as a result the women all begin to flee the mansion. As Venomania dies, he sees a glimpse of Gumina and he begs her to stay, as he states that he has not yet told her that he loved her.
Uh, so theres this vocaloid song i really like... Its called The Madness of Duke Venomania.