The top one is Crona's sex so it's what he biologically is. Gender is what YOU process as. Crona has never clarified for us so yes it is unknown. Either way Crona is still my favorite. Right above Kid.
Oooo this would be way interesting. Though I think that they are geniuses in two different ways. I think that L is a genius of deduction, while Shikamaru is a genius of battle strategy. It would be interesting to see them play shogi.