One thing that comes to mind from the modern era for me is that Score Attack mode in the first BlazBlue. That’s gotta be one of the hardest single player modes ever put into a fighting game…basically the difficulty for that is “special” as it goes beyond the game’s highest difficulty setting for anything else. The first opponent will destroy you in about 4 seconds, usually. In fact, I’m doubting it’s even possible without using either of Tager or Jin… I used Tager. It almost turns the mode around into something easy when you pick that character, but he still has a problem with v13 since her whole deal is to throw magical teleport/spawning knives out of nowhere all day long. The cpu’s Unlimited Ragna against anyone else besides Tager is a rape simulator. I can’t remember the last time I’ve seen a character that ridiculous in a fighting game, actually. You will die in 2 or 3 seconds…unless you’ve decided to win by picking Tager, of course.
on another note— the “A-Rank” CPU characters in Soul Calibur 5 can and will get Perfects on you pretty much whenever they feel like it.
*Back in the day, despite my hellish experience with NES Battletoads… I actually bought the Gameboy version when it came out… apparently I thought it might be better and actually possible then… I was wrong. You still had to be Jesus Christ to stand a chance of beating that. The people who worked on the Battletoads franchise should’ve been banned from this industry.