/ic/ - Artwork/Critique

This is the main character of the graphic novel I would write if I weren't a /beg/ tier artist. He's a freelance mercenary who gets a once in a lifetime contract to take out a cult leader who's Threatening a peaceful village. But the job gets a lot more complicated when it turns out all the local warlords joined the cult and his target has demonic powers. The whole book would be him killing them all off one by one. There would also be a romantic subplot where he slowly falls in love with the assassin who the cult leader hires to kill him, and she also develops feelings for him. They try keep up the appearance that they want to kill each other, but they both low key like one another. I have this whole moment in my head where they finally drop the act and kiss, but again I can hardly draw more than two characters interacting with each other.

How do I draw the hands better so they don't just look like fingers coming from the wrists? And I want to get better at positioning the arms so they look more natural. I also want to know how to shade better than just randomly scribbling, and how to make it cleaner.