Shiki has black hair, scarlet eyes, and somewhat pale skin. He is almost always seen with a katana; and is shown to treat the blade with utmost respect. Standing at 188cm and clothed in solid black, he is an intimidating figure. Due to the fact he slaughters the participants of Igura without any apparent rhyme or reason, he is high feared and dreaded, with anyone who encounters him turning tail and running for their life. He is shown to be one of the strongest (if not the strongest), people in Toshima, able to hold his own against both Kiriwar and Gunji in a fight.

Spoiler

He is Rin's elder half-brother (they share a father). He is also revealed to be the undefeated drug lord 'Il-Re'.