EDIT: I beat it - turns out the game was running at a subpar framerate in fullscreen causing me to always mess up the zandatsu slashing thing. When switched to windowed mode it ran at 60FPS and I had zero issues getting through that section.
So I've just spent an hour on the final boss. Let me say that I didn't have many issues during the span if the game or any of the other bosses. I understand parrying, although I think it's a clunky system because it depends on which way you're facing the enemy and the camera is awful in this game. That said by the end I was really starting to get into it. The cheesy rock music, the awful dialog - it all came together in this ridiculous package that leaves a grin on your face.
My main issue with the boss: there is a zandatsu (sp?) moment when he jumps and hurls debris at you. You have to cut it along specific lines three times before you get a chance to hit the bosses head - or so I hear. You see I've yet to get a chance at slicing the senators head as I've barely time to clear the debris without getting hit. When he hurls the chunk of stuff at you I hit the cutting mode left trigger and..the stuff is always very close to me. So close that the second cut is filling the screen and by the third cut it's almost on me.
I don't know if I'm missing a prompt or what. I've tried to hold the trigger before he throws it, press the trigger the moment it starts flying at me, waiting for the Japanese text to pop up on screen. Nothing - the first section is always too close for me to be able to cut everything in time to get a chance and hit the boss. I can always clear these sections but never with enough time to damage him.
I've managed to get him down to 20% health once, by just pure swordplay but the problem is I have no healing items going into the fight. I'm decent at the game but when each of his attacks take off 30% life and his myriad of AoE moves make it a precarious battle with a single lifebar (although it is at 160% health).
I'm just shocked as I haven't hit a wall in a game like this literally in years. I also feel humbled when I see no one else seemed to have any issues with it. So humble bombers, any tips?
(Disclaimer: I wrote this on my phone so apologies for spelling errors)