Ok, so my first requested exemplary feedback. Ok, so the idle animations are really good. The breathing effect is done nicely. About the position of the knife on the thumb, you could have improved them by making some more movement, like the brushing out the knife against the thumb. Take it as a point of improvement.
About the draw anims, they are fucking perfect! When doing draw anims, the animator should note that draw anims is actually the pre-event :P of idle anims. By this I mean that technically, the last frame of the draw anims should have a follow-through effect to the first frame of the idle anims, which has been done flawlessly in here.
Stab anims, they are also realistic and flawless.Not much to say in that though I really like the jerk on the hit, and then the fast recoil/come-back and then slowly returning to the hand. The left hand's movement also follows realism.
The thing about the midslash anims is that you have made it too smooth. Try adding some more force at the start of the slash, and a good stop force at the end. Again, I really like the breathing force on the hands when the knife returns to idle position.
The slash snims, they look a little unrealistic when you slash. This is because you moved the knife in an oval path, like a parabola :P Try making it like, add a force to bring out your knife, slash it straight or diagonally and then stop it, return to idle.