Riliane Lucifen d'Autriche was the last Princess of the Kingdom of Lucifenia, regarded as The Daughter of Evil, and the twin sister of Prince Alexiel. Separated from her twin in a political dispute during childhood, Riliane grew up in a lavish lifestyle, ignorant of her past. The selfish Princess was unknowingly possessed by the Demon of Pride and, after her mother's death, became Lucifenia's monarch. An arrogant tyrant, Riliane became despised for her terrible regime, aided by her loyal servant, Allen, in exterminating any opposition. 

A vast kingdom called Lucifenia, whose popular name was the "Kingdom of Yellow," was ruled by a tyrannical fourteen year-old princess named Riliane. Under her absolute monarchism, everything was exploited from people and the ones who did not obey her were executed without mercy. Allen, a servant who looked a lot like her, was always beside the princess whom Lucifenia's people called the "Daughter of Evil." The princess and the servant were the same age, since the two of them were actually twins who were separated shortly after their birth, with Riliane taking her mother's position as the country's ruler and Allen works in the palace as a servant since he was given up for adoption. The princess's selfishness and jealousy caused a war and many deaths, and their secret clockwork of fate was going to spin madly.
 
(Source: Vocaloid Wikia)

A vast kingdom called Lucifenia, whose popular name was the "Kingdom of Yellow", was ruled by a tyrannical princess named Rillianne and she was still only fourteen years old. Under her absolute monarchism, everything was exploited from people and the ones who did not obey her were executed without mercy. Allen, a servant who looked like her, was always beside the princess who was called "Daughter of Evil" by the people. The princess's selfishness caused a war and many deaths, and thus the secret clockwork of fate was going to spin madly. 
(Source: Wikipedia)

"We have done nothing but make mistakes."
 
What does the boy see at the end of the never-ending cycle of death and rebirth?
Thanks to the actions of Allen Avadonia, who once served under princess Riliane as the "Servant of Evil", Nemesis recovered her lost memories. As the sole survivor of the ruined world, she journeys with Allen to "Evils Theater" in order to uncover the "key" needed to save the devastated land.

The major power of the Evillious region, the Kingdom of Lucifenia. Ruling this vast country was the 14-year-old princess, Riliane. She used her absolute power to squeeze everything from the people, and anyone who defied her was beheaded without mercy.
 
(Source: The Evillious Chronicles Wiki)

4-koma short stories depicting humorous "what-ifs" in the Aku no Musume story.

The story follows Allen Avadonia after the annihilation of the Millennium Tree Forest by "Punishment", sent on a journey to meet the souls of individuals involved with the vessels of sin by Sickle.