Nice ideas, all of these. Honestly, I don't know who it is. Speculated a bit, but one thing to remember is the constant ability of writers to throw little things in the stories that totally alter it. Could be a hero. You know, the butler did it. Like, first thing is, no sign of forced entry. Maybe a friend came by or something.
But in the theory it is a villain, Shade sounds good, but I don't think they would have given the name right away. Story seems to be one where there is more that has yet to be uncovered. Each step, something new. First issue mentioned Dr. Light at the End. Second Issue discussed magic lobotomies. Third discussed a lot of lobotomies and had another dead chick. Soo... I am thinking, Identity Crisis might actually be something like a hero who used to be a bad guy. Or something like that.
Amazo kind of gets ruled out. On account of not having a real mind of his own. Still. Interesting observations.