I did a comparison of some blue black inks last night — Edelstein Tanzanite, Iroshizuku Shin-kai, Montblanc Meisterstück Blue Hour Twilight Blue, Sailor Bung Box Blue Black and Kaweco Midnight. I used two pens — my super dry Sailor Pro Color and a wet Pelikan 400NN with a medium nib and some flex (see photo below). Paper is Koyuko binder paper.

My tldr: I need some better lighting.  EDIT: Now with better lit pictures! Slightly.