The center piece of each drawing is obviously the Killer and as a visual addition there are several brush strokes. They are colored red (as in blood). Furthermore, they are guiding the eye or focus on important things or help explaining some of the art. Above and beneath each killer is a Kanji sign. The top one is always “negative” or evil (for example “poison”), while the one at the bottom is “positive” or good (for example “honor”). The idea is that not all of them are straight evil and YOU get to decide which way you want to lean in regards to the individuals. What helps immensely making a decision is the fact that each artwork/ killer/ assassin has his/her own haiku poem accompanying them. Those shed more light on their back stories. Moreover, at the edge of the art you will find a general description of their location in which you can approach them at a certain time to make a contract. They vary a lot. By the locations and time you can make some assumptions towards their charters.
It was an extremely fun task to assemble each character and decide what personality she/he is going to get. There are a ton of cool references in there as well (Akira, Ghost in the Shell, Scott Pilgrim and a dozen more). I loved making the Killers and I really hope you will tell who is who. Who leans towards the dark and the light? Also, if there are any additional questions I am always available.