Plot hole: In the very first episode, the Wu Assassin (who hasn't even been properly trained yet) is fast enough to dodge bullets, that appear slowed down to him, leaving a trail behind them. At no other point in the series does the assassin exhibit that sort of speed and reflexes - in the penultimate episode he definitely can't dodge bullets, although the villains use automatic weapons so the comparison is in part unfair. It sure seems that he has been 'nerfed', or that he was accidentally written too overpowered in the first episode.
Suggested correction: I watched the scene and there's nothing to indicate he's seeing the bullets appear slowed down for him and he's not dodging bullets from his incredible speed. He's just zig zagging in a narrow hallway as he approaches the shooter, causing the shooter to miss because he doesn't know where to fire at (not that he was a skilled shooter in the first place.) He didn't dodge the first shot, he just reacts to a bullet going by him so closely. The bullet trail was a visual effect for the audience.
He's literally following the first bullet with his eyes, turning: the trails are there for the audience but it's a fact that he turns his head to the first bullet and dodges the second moving out of the way once it has been fired already, and he moves out of the way of the third once the shot has been fired as well, I call that incredible speed! That scene looks way more matrix-y than it had reasons to be compared to the rest of the show, imo. And he has not been trained yet. Valid point that the guy was most likely a terrible shooter and the last couple of shots are bad misses to begin with, but the bullet speed is the same anyway once a bullet has been fired, regardles of who fired it. I upvoted your comment though because I appreciate feedback and if your different perception of the scene is important.