|“||You're the royal highness and I'm your loyal servant. We are two star-crossed twins who can never be together. If only I could protect you from all the darkness. I will do whatever it takes to become evil itself.||„|
|~ Allen swearing himself to Riliane and admitting his villainy.|
|“||If they call you evil that means I'm evil too, for we share the same blood, you are me and I am you.||„|
|~ Allen to Riliane|
Allen Avadonia is the secondary antagonizing figure, supporting protagonist, and one of the central characters of the Vocaloid song series "Story of Evil".
He is represented by the Vocaloid Kagamine Len.
When he was a child, the prince Alexiel Lucifen d'Autriche and his twin sister, Riliane, were very close. One day at the beach, the two accidentally released a demon. Alexiel showed the demon kindness, and in return the demon told him that if one were to write a wish on a piece of parchment and send it into the sea in a bottle, the wish would be granted. After an attempt on Alexiel's life, Alexiel was pronounced dead to the public and was adopted by the captain of the guards, Leonhart Avadonia. Taking on the name Allen, he formed a bond with his new sister, Germaine Avadonia. However, after the death of the queen, Riliane rose to power and Allen came to work as a servant under her. Even after saving her life and gaining her trust, he went unrecognized by his sister.
While running errands in the city of Aceid, Aleen met and fell in love with the beautiful green-haired Michaela. However, after Riliane's marriage proposal to Kyle Marlon was rejected because of his love for a green-haired girl, Riliane ordered that Allen go and kill every woman in Elphegort with green hair. Allen reluctantly obeyed and began a massacre of every woman with green hair, including personally killing Michaela.
Lucifenian Revolution and Death
After the genocide of the girls of green, Allen continued to serve until a revolution against Riliane (led by Germaine) began. The people demanded a new era of change and were set on capturing and executing Riliane for her crimes. Before the castle was attacked, Allen revealed that he was Riliane's brother to her, then demanded that they switch clothes. Riliane would dress as a servant and escape while Allen, looking the same as her, would pose as the princess and be captured himself. Riliane reluctantly agreed, and Allen was taken captive.Days later, Allen was to be executed via beheading, with everyone believing he was Riliane. Still impersonating her, he went along with the sentence. His last thought was a wish that he and his sister could be together in another life. He was then beheaded and died.
Afterlife and Reincarnation
Allen's spirit went to the Heavenly Yard and had encounters with gods and deities. He served as a watchful spirit over Germaine and Riliane. He later fell into a a decades-long sleep that ended with his reincarnation into a human boy "Kokutan-douji".
Allen appears as a thin boy with bright blond hair and blue eyes. He usually wears a black and yellow suit or a dark brown cloak that hides his face.
- His original surnames, Lucifen and d'Autriche, are a reference to Lucifer, the patron demon of Pride, and Marie Antoinette, respectively.
- His adopted last name, Avadonia, seems to be a corruption of Abbadon, meaning "destruction" in Hebrew.
- Allen's name is partially inspired by the name of his representative Vocaloid, Len, using "len" at the end of the name; similarly, his birth name, Alexiel, shares the "le" with Len.
- Allen was executed the day before his fifteenth birthday.
- He shares the same birthday (December 27) with his Vocaloid.
- Like his father, Allen styled his hair in a ponytail.
- Some believe that there is subtle evidence of an incestuous relationship with Riliane, though this has never been confirmed and is most likely false.