I think you did a wonderful job of combining all the essential elements of superhero action with the extreme foreshortening elements of the limbs captured in a moment of action. Although with the name of Vampirella perhaps I should say shes a super villain. Or maybe she a combination of both which gives her a mysterious past history, perhaps on the dark side.
Your inkwork is excellent. Youve created very good effects with it like the high glossy sheen of her hair, her boots and the wrist and arm bands. The knife is also highly reflective. All of this is very good, especially considering youre self taught. Foreshortening techniques like you draw in her arm and hand are very well done, and a hard thing to do, so I think youre a natural at drawing in the arena of comic book characters and for a first attempt at using color you did really well.
The figure is framed very nicely in front of the circle which I assume is the Moon since vampires live at night. I like your use of painting the right side background in light colors and the left in dark colors. It creates a good composition. The Moon and Vampirella being centered on the page catches the viewers eye in an electrifying and dynamic way, and the use of unblended lines In the background and throughout the canvas creates a lot of visual interest, giving the impression of a lot of movement and action taking place.
And Im left also aware that youre telling a story in this drawing with the bloody knife in her hand. She has just slain someone or something and the blood is fresh and flowing as she seems to land on her feet and look back at the observer who is the viewer. The observer is the creature or person who has just been wounded. The look on her face seems to say she knows youre not long for this earth. Its a look of supreme confidence in her slaying skills
You have all the essential qualities of comic book art and your use of color isnt bad at all. It would be interesting to see how you develop this new addition. I would read the comic book just based on this picture. I hope your story as you develop it is as good as this art.