I have a suggestion to when he lifts the sword. I was gonna show an edited animation but ImageReady weirded out on me, making the animation grey and black only. 

Here's the frames I changed anyway.




Since the sword is supposed to be very heavy having him hold it perfectly horizontal breaks the illusion of weight.

I did not really mean to offend, sorry if it came out that way.

unge forward BUT DON'T let your foot touch the ground until the tip of the sword does....

 ...so why would you balance on one foot until your attack lands? Undecided I'm not saying he should step.....wait....swing, for that would be STUPID, but rather, I'm suggesting the step take place DURING the swing rather then on the exact same interval of time.

I see where you're getting at. However, when we make these kinds of swings during training we aim to begin and end the swordcut and movement of the feet at the same time. The closer, the better.
Simply because it's supposed to be one move, not two moves happening at the same time.

To me, your biggest issue with the attack animation are two things; pacing and the angle of the sword.
As it is now the attack moves at the same speed throughout the animation, there's no buildup and no snapping motion.
It's looks as if he just lets the sword fall down, not applying any force.

As for the angle of the sword, the character does some pretty weird things (aside from moving the elbow in front of his face).

This frame is perhaps the biggest issue in the animation. The angle here is what you'd get from a near completed swing,
yet most of the sword is still above his head. And he holds the sword in an almost impossible way. I can imagine an actual
sword like that, swung that way, could end up injuring your wrists since the awkward pose puts strain on the wrists.
I did a quick paint-over of how he should hold the sword when his arms are in a similar position.


I totally agree with ndchristie about breaking up the animation in two parts.
Swinging the sword forward and positioning it above the head with the help of the momentum of the swing
would probably take less effort than just lifting it.

Also, it makes more sense to make a swing since he wouldn't leave himself vulnerable then.
I also did a small animation of it (uncannily similar to ndchristies too )


I also notice you contradict yourself. With the walking animation you wanted to make him drag the sword like he has trouble with it.
With the attack you want him to swing it without effort.

I imagine the sword to be rediculously heavy so it'd be pointless to try and carry it in the air.

If he could wield the sword effortless, carrying it around would not be a big problem.
I'd suggest looking at Siegfried from SC3 (if you have access to the game, play it and study it. if you don't have it www.youtube.com)
He wields a huge sword (granted, not "Gats" huge but still pretty big) but does so effortlessly.
Siegfried is a very good example of "huge sword guy" done right.

I reckon the "slow struggling attack" you mention is the actual buildup for the attack.
The buildup is necessary for such a big sword. At least to make it look convincing.

Hope it helps 

Ah, I see what you mean. Totally missed that.

Attempted to fix it. Also made a few adjustments to the scarf, and pushed his other arm up one pixel.