So, I was able to defeat Luke, but that was only after slowing down the text speed in the settings so that I'd have time to see the warning about what Luke's next attack would be. Since the timing given to choose a prompt goes by very fast, that just barely gave me enough of an advantage to defeat him.
Edit: OMFG there's another fight right after Luke's, where you fight him and his henchmen....

PLUS you can't save between fights, so if you loose, you go aaaaall the way back to the very first fight.