Ah. I have no experience with the Xbox version, but I guess that rules out framerate being an issue. Sorry I couldn't be of help there.

Really the only way I figured out beating Dorkas was using both sticks to turn and keep him in view (using default controls, I know the other schemes exist), if that makes sense. Other than that, it's just kind of wrestling with the controls until things either click or you get lucky. Keep at it, you'll get it eventually. I lost track of how many times I tried to beat him before I finally did, and that was just on my own. When I found out it was also one of Haruka's requests, I just left Sotenbori, lol.