The last time I tried to play No More Heroes 2. I never actually played the game on the harder of the two default difficulties before this. When there's only two it's kind of hard to tell which one is supposed to be the "normal" one. So I went through on the harder mode this time, and most of it was totally fine. In fact a lot of the bosses were still pushovers. Although I did have trouble with some of those 2D training minigames. But anyway, I get to the final boss, and hit a huge brick wall in the second phase. Literally minutes from the end of the game. He has this attack where he teleports around the room, and then behind your back, and cracks you with a really powerful and unblockable attack that is simply too fast to see coming, and that knocks you down too. Although he doesn't always do it right behind you, and the angle he comes from is totally unpredictable. Also he can stun-lock you with this by doing it over and over again, which he does frequently. And just to make things even better, if you are vaguely on one side of the room, his attacks can knock you out the window and kill you in one hit. There isn't a clear barrier of where the danger zone is, but it's definitely way bigger than it reasonably should be.
Luckily I did have the foresight to have rolling saves, so I went back to when I still had access to the training minigames to increase health a bit. I still couldn't improve much because those minigames are bullshit too, but by the time I got back to the boss with improved stats, it didn't help much anyway. If anything, I did worse, just because he kept stun-locking me with that bullshit move even more. The game in general does have some weird difficulty spikes because, as much as I like it, it uh... isn't very well designed. But this was just impossible. Ridiculous bullshit that relies on total RNG luck, where you are far more likely than not going to get fucked every time. I wasted several days on that bollocks, and had to do the final level twice, just to finally have to throw in the towel.