I know it's not my place to criticize, since I'm neither an animator nor a martial arts practitioner.

But wouldn't you agree that Waterbending should be more fluid in terms of choreography?

I really love the part where the Waterbender cuts through the rock wall. But otherwise I felt like this Waterbender fought more like an Earthbender at times: such as when beating down on the rock shell, and when standing on the ice.

A Waterbender may not be constantly moving and dodging like an Airbender, but she is always ready to counter an attack, turning an opponent's strength against them. Water is fluid; it can slip, it can flow, it can crash, it can freeze. A Waterbender can deflect, or even catch large boulders and whip them back with increased momentum and an elegant spinning flourish. A Waterbender can surf or ice-skate for mobility, slipping through openings and maintaining a continuous assault from all directions. Even when a Waterbender is forced to face an attack head on, it is almost always with an instantaneous follow-up action, usually obfuscating their movements with the opponent's previous attack (which is why I really like that wall-cutting-part).

Waterbending is a style that excels at reacting to an opponent's actions. An Earthbender is most advantaged with his emphasis on Neutral Jin, which can trick the Waterbender into a corner they can't slip out of. A Firebender is at the greatest disadvantage, as all he can hope for is a successful preemptive strike - a skilled Waterbender wouldn't drop her guard against such attacks. Airbending is very similar to Waterbending, and thus there are no significant advantageous and disadvantages.

Fire > Air > Earth > Water

Fire VS Earth = A high-stakes stalemate that could swing to either side at any moment

Air VS Water = A battle of attrition requiring patience and continuous focus

Hope my 2 cents results in more amazing animations!