My two favorite Issun moments:
1. When you first fight Orochi, I tried to waterspout the sake into his mouth when it was just open (not roaring). At which point the action stopped so Issun could lecture me on how I was doing things wrong. In the middle of a boss fight. A major boss fight. Everything comes to a stop so I can be put in my place for waterspouting the sake at the wrong time. Great.....
2. When you fight the 5-point Blockhead on Oni Island. I'm not good at that sort of quick memorization, so it took me a few tries (like 15+) to get past it. EVERY SINGLE time I failed, he gives a "C'mon furball, you mean to tell me you forgot....you have to paint in his weak spots" speech. After I got past it, I saved at the first save point and turned it off for the night, I was so pissed.
Honorable mention: His constant drooling over "busty babe" Rao AND his constant "I don't like you because.....I don't and that's that!" attitude he has towards every single non-female character.
I think my favorite part of the game was when you enter the Ark of Yamato and Waka totally owns him with the "you're not worthy of being here" speech. Just knowing I'd get a few minutes of gameplay without the constant high-pitched beeping of him chattering provided all the adrenaline I needed to wipe the floor with all the Ark bosses!
I'm not afraid to die because I am invincible
Viva la muerte, that's my goddamn principle