Hardest Video Game Boss/Enemy

[Sirion]

I don't know his name. The boss from Samurai Shodown V. He was just so much overpowered I had to set the game for me to only need to win two rounds, while the computer needed to win five or six. And still I got beaten all the time! I think I never used save state so much (I'm not proud of it, though. I'm not a cheater). When I finally managed to beat him, the big frustration: the ending is nothing but a text rolling on the screen! IN JAPANESE!!

AAAAAAAAAAAHHHHHHHHHHHH!!!!!!!!!!!!!!!!!!