That looks cool! That one arm is a little big, but the pose itself is very dynamic and very interesting to look at! Good job, and great choice.
Some proportion issues, like the forearm being much longer than the upper arm. Also i would make the fist and hand bigger to emphasize the pose, maple sprites have a messed rule about hand sizes, so you are free to make them bigger or smaller when you need it. Another issue s the way you positioned the limbs, like the left elbow should be closer to the body below the shoulder. The back leg should have a more bent knee while the front one is stretched. The torso should be rotated more towards us and tilted more to the front. The arm holding the sword should make a 90 degree angle. Yeah, that's pretty much it.
