Page 8: Candy reacts way too dramatically in the last panel. Is reincarnation that mind-blowing to her?
Page 10: Candy is apparently a dumb nerd. So why is she so serious about this random mythology trip?
Page 12: There've been little spelling and grammar errors scattered all over the place so far, but "interacted with her" is just about the strangest word choice I've seen in a long time.
Also on page 12, in the second and third panels, you may want to change the tone of the girls' clothes just a bit so they're easier to see against the background. Either that or change the background a bit.
Page 22: Why does Candy equate a serious expression with hiding something?
Also, what in the world is Candy going on about? Marissa talked about reincarnation, and somehow Candy knows she's reincarnated? Yeah, it's obvious that she is, but how in the world did an off-handed line about mythology--which, by definition, is not true--convince her that she's special?
Page 23: Ah, this explains a bit. Still, how does she know that's where her wind power came from? She says, "too soon to believe in a theory," but it's really obvious that the theory is correct. Maybe to shake things up a bit you could remove the prologue sequence in the beginning and then offer up some more theories and have Candy try to figure out which one is real?
Page 29: That kid looks just a wee bit old to be ten.
Page 31: What Candy reveals in the fourth panel is actually a fairly decent backstory. But why tell us it rather than show us Candy being conflicted over talking to people? She also talked to Sophie pretty easily, and if her emotions weren't strong then, when would they be?
Page 38: Seeing your parents dead IS traumatizing. So much, in fact, that 100% of kids who see a parent die get PTSD. I'd have to assume Marissa has it, and now I expect it to show.
Page 39: Yeah. Like that. It's not usually that extreme, but I can believe it in this case. The gunshot wound doesn't really look like a gunshot wound, though. It looks like a bruise. Also, you may want to look up what it feels like to be shot. I don't think Candy would be have a straight face after that.
Here's some references to save you some search time:
Page 40: Yeah, way too straight-faced after taking the bullet. The first few panels are all right, but then she just settles down and keeps talking. Again, doesn't look like a bullet wound.
Overall, despite the implied serious nature of the story, it feels kind of fluffy, and it wasn't any one thing that created that feeling. Candy's reactions to everything, the way the blood is drawn, how the camera doesn't show any direct, dynamic action sequences (Candy and Sophie crashing into each other, Candy being shot), and the stereotypical prologue/epilogue sections that pull away from the main cast to show more important people talking about more important things all contribute to a manga that feels--well, like a manga.
That's not a bad thing, necessarily, because it's a manga. It just feels like a generic urban fantasy with nothing unique to make it truly great. You've got all the basics down: good art, paneling and dialogue balloons that let the reader's eye flow from one to the other in the proper order, and a decent story and characters. There's really nothing inherently wrong with generic manga. People will still read it and people will still like it. If you want to be truly exceptional, however, you'll have to do something that's rarely, if ever been done before, or you'll have to do the same thing everyone else is doing, but on a much higher level.
Also, spelling and grammar. I know you're not a native English speaker, so I could help with that if you'd like.