Luka has unkempt blond hair and golden eyes. His fingers, from the midsection onwards, are a vibrant purple hue due to his asthma and congenital heart disease. He can frequently be spotted in a white blouse with an uneven hemline, which is cinched at the waist with a belt. A sizable and lengthy bow is positioned at the back of his collar. He dons a pair of black, ankle-length slacks and plain white shoes.

Luka is calm, charismatic, cold, aloof, manipulative, smart, and cunning.