I'm basing an icon on an early depiction of Jesus and want to,,, should the non-Jesus figure have a halo?

I'm basing an icon on the earliest known depiction of Jesus, called the Alexamenos graffito, also known as the Blasphemous Graffito. There are symbols in the carving that, while intended to be insulting, actually have basis in Old Testament and New Testament as far as being despised of men, the Torah and royalty being symbolized by a donkey, and so forth. The figure of the Crucifixion isn't up to debate, then, but there is a question as to the Alexamenos figure. There is, to my knowledge, no saint by such name, yet he is shown 'worshipping his god', and since this graffito was produced in the 1st through the 3rd centuries C.E., it is possible that he was later one of the many anonymous martyrs of the early persecutions. My question is this, since there is no known Saint Alexamenos, should he have a halo to represent the many unknown martyrs, or should he be left without a halo in the icon?