First I made with CapNs running tutorial.
An addition to it.
I was so bored. (Fatality)
That loser died.
Whats your favorite?
Running: it simply looks like the guy is jumping while shaking his legs and arms; add some frames in the middle to show the switching of arms and legs, and it will look much better.
Sword + Running: Same for the legs, but also-Who carries a sword that way? Imagine holding it like that while running, your arms would be so taut to the sword's grip; it feels awkward. It looks twice as awkward when you're watching someone else do it. Move the sword; Traditional under-the-arm style is generally a good place to start.
Fatality: The "crosshair" goes behind his head? He also looks a bit like he's trying to take a squat, and when he gets shot he moves slightly to the left, gets a bullet hole in the head, but doesn't drop or at least lose the stiff joints?
Pistol: The shooter only moves his head while firing; add some recoil to the arms, because if that's a deagle he's firing he's gotta be superman to hold it that still. The victim falls kind of flatly, and his feat fall out from under him; Make arms drop, and follow his center of gravity down to figure out how he'd hit the ground first. The way he is shot he should bend his back a bit backwards, then begin to fall and his back straightens up normally again due to the falling motion, before his arse hits the ground and everything else follows.