His form is that of a person or person like thing in a fullbody metallic suit, it is hued bronze and black with a gas mask as the face. On his hands are blades instead of fingers which he is somehow able to move. He is very sadistic and maniacal to the point of utter ruthlessness. Upon appearing (mostly in cutscenes) a scissor scraping noise is heard.
His use of a mask represents his lack of humanity in a similar way to pyramid head, the gas mask also resembles one that Henry saw when he was a child at a world war 2 museum which adds to this idea.
As the literal embodiment of Henry's dark side he first appears when Henry looks in the mirror and sees his reflection as Edward's.