as jsalwen said, you just need to be more consistent in the anatomy in the first batch of drawing the heads are bigger than they should yet in the second batch you're more consistent, in particular the Colossus and Hellboy drawings.
It's cool to try out various styles, i'd say forget which style you want and practice your basic body construction, from there tighten up your anatomy and your style will then come naturally.
For the most part artists tend to start out by imitating other artists because we like how they look, i wanted to be a Jim Lee clone bad, but after years of trying i would up with my style instead. It had its origins with the Jim Lee look but it soon evolved into my look, my style.
My advise, think of an artist you like and try and aim for the look, but, using your knowledge of basic figure construction and your knowledge of anatomy, but dont draw what he drew. It's cool to pick up a few shorthand shortcuts from artists and incorporate them into your style, just dont steal or "clone" the whole look.
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