I love most of this Zero sprite. It has nicely added CPS2 colors, and it resembles the same style as Megaman in MvC. Only things bothering me is his face, which kinda makes me see it as if Megaman was wearing the helmet rather than Zero, and the hair, which does seems a bit too thin, and could use a bit more of details in either the shape and/or the shading. What I can suggest about his face is that you could give an impression that his pupil is slightly more thin, because that's how Zero's face design is kinda like.
Oh I see it was just a style choice, makes sense. I do remember those characters having the outline but I never understood why lol. Well whatever it still looks great. Your work is always quite nice in whatever style you make them. Can't wait to see more. Are your new MVC sprites going to be featured in the new MVC Udon book?