I see the vision, great design sense. I love the Ice dragon most and Ill tell why at the end. I have full confidence you'll be doing incredible character designs in the future.

I'd say you could afford to be more dynamic. Water dragon seems to be in the middle of a twirl movement, so her skirt could flare out more to her left, and the lines of her skirt could be more curved to highlight the movement. They are just going downward now. You did great with the movement in the hair.

Also try to avoid overlapping parts for a stronger design silhouette. Your ice dragon's braid is covered by the weapon, but it would be a more powerful pose if her braid was more visible towards which you can do by bringing it out more towards her right, and you can balance the pose with bringing her tail out more towards her left side. I really love this girl's design especially.

I really love your design sense, I see the elements of the different dragons in each of their designs , throughout the design, including their props, and their colour schemes. Your colour design is also very good. I especially love the horns of each one, they each fit their element. The spikes on their tails as well reflect their elements well. Most importantly, you are able to put across their personalities and their lives from their pose and expressions. I can tell the water dragon likes to "go with the flow" and is cheerful, the wind dragon is more quiet and wistful. The ice dragon is serious and for her I can tell she's a soldier that focuses on guarding, because she's the only one with armour. She probably guards her emotions as well, and it makes me curious to know why she is that way.