Let's talk about repetition in fighting games.
For the most part, my focus here is on Soul Calibur 3, which is where I became most aware of how freakin' ridiculous this is. A number of your opponents can be classified as unrealistic, bullshitty, and made of fail...because there are cases where they will use the exact same attack again and again for reasons that must be entirely due to faulty programming. This is a fighting game, where the beauty is in the elegance of the match as two opponents beat each other senseless. It is NOT clever in any way - for instance - when you get knocked over and the AI decides "I'm going to the exact same attack to hit you when you're down just to dick with you.". This is not an intuitive system. This is a bad AI.
After all, it's not physically possible for the character to keep doing that if this were a real battle with real people. And real people wouldn't do that either, because it's stupid. This was where the programmers got lazy and put in an If-Then statement to repeat, FOREVER. When that happens, it gets unfair because it's a reliance on the cheap to win instead of real skill. And when THAT happens, I feel more and more inclined to say "Fuck you, game. I'm cheating, then. NOW, who's the god, ya cheap bastard?". Because, last I checked, nobody liked skill-spammers, people who are one-trick pony fighters who never try some variation in attack. Buttons-mashers, we're cool with, but those? No.
So, cross-reference the irritation of skill-spammers with "AI Is A Crapshoot" and "The Computer Is A Cheating Bastard", and that's pretty much my entry right here on the unfair. You'll be happy to know that I don't see this too often in other games I like, but it's there...sometimes.