A pale man with black eyeshadow and a feather in his mouth, he was ordered to stand in court despite technically serving a murder sentence; made quite clear with the large pair of handcuffs connected by a chain on his wrists. Blackquill also carries a hawk named Taka on his right shoulder. Blackquill uses psychological manipulation techniques. He also has his own interjection in court, which is "Silence".
- Simon's English given name "Simon" comes from the Classical Hebrew "שִׁמְעוֹן" (shim'ón), meaning "hearkening" or "he has heard". His last name, "Blackquill", is a combination of "black" (dark colors being prominent in his character design) and "quill" (a writing implement made from the molted flight feather of a bird).
- His character design, along with having an avian companion, is similar to Setsuna from The Last Blade 2, a fighting game developed by SNK Playmore.