Guess 1: Justice League members who wear or have worn gloves. (J'onn acquired them with his latest costume.) (Atom, Green Arrow and others couldjoin this list)
Guess 2: Justice League members who are detectives. Obvious detectives: Batman, Elongated Man, Martian Manhunter/ John Jones. GL: Space detective/ Corps officer. Aquaman: Undersea detective. (yeah, this guess is kind of stretching definition of detective)
Guess 3: Characters killed or rebirthed by Didio.
I'm gonna reveal the answer tomorrow, sometime in the afternoon, I think. This one WAS prob'ly the toughest one I'd come up with!