Allen is a slim wizard in his 20's with half-black and half-white hair and blood red irises, he also sometimes wears a ragged hood.

Allen is a kind person but can appear scary whenever he gets angry. He is firmly against gaining any kind of title due to the hassle that would come attached to it which is why he refuses to take up his adoptive fathers position of the Chairman of the Athena Magic Academy.
Allen once a former adventurer who joined a certain party hoping for a fun adventure, la. Later, he broke the seal of a temple, and he was left for dead in front of a horde of monsters by the party's members. However, he returned and revealed to the Adventurer's Guild of his former companions' crimes as well as having the Guild post bounties on his former "companions".

Allen then started to live in a forest, but he is known as the "Demon Lord" and is feared by those around him. One day, while living his life as a hermit, he comes across a young girl named Charlotte who has collapsed in the forest. Despite being innocent, she was accused of evil deeds, had her engagement annulled, and was forced to flee her country. When he heard that, Allen remembered the agony of being betrayed by a group he once thought was his companions. After hearing the story of the 17-year-old's exploitation, Allen decides, "I'll let her live in my mansion, and I'll teach her all sorts of bad things. Allen has a younger sister, Eruka Crawford. His father is the chairman of the Athena Magic Academy, and Allen was one of the best students who graduated at age 12 to become a teacher. He revealed he was adopted by the Crawfords after his real parents died.

(Source: Konyakuhaki Sareta Reijou wo Hirotta Ore ga Wiki)