I did quite well on nearly all of the battles including the knight, but I just don't get that sorcerer.
To me it seems like the fireball sound in the moment right before it hits you is at a different soundlevel depending on the position in which the sorcerer fires it, when of course it should be the same.
When he's right in front of you the fireball sound is at max the whole time, while it's half as loud before you die when he's farthest. This would only make sense if you intended it to lose power over the time it flies which I assume you didnt.
Plus there should be a better way to analyze your death cause. If in the above case I can't be sure where the fireball is, I can at least remember the different soundlevel of the close fireball for the different distances right? The problem is, that there is always the chance, that I just didn't stand in the right angle to the enemy, resulting in even more confusion as I try to adapt my strategy.
It would help if there would be an indicator where something hits you so you know whether it came from the side or from the front. He does feel pain, I guess.
It does not help either, that the sorcerer speaks his lines in different volume levels so it's even more unclear where he stands, which I can accept as a circumstance that makes it more difficult but is not unfair.
Of course it could also be that my ears suck. In that case forget what I just wrote.
One last thing though: it was never made clear, if it makes a difference whether you press the blocking key longer or not.