@Local-chan:
All are playable during the main game yes.
Sogeking is one of Usopp's specials much like Rumble Ball.
Nightmare Luffy I believe you have to have 100 shadows and then Luffy die (dunno. Never used him)
Monster Chopper is different on each game. In the first game I got him against Nightmare Luffy, went something like this.
Zoro took off a chunk of Nightmare, Brook did something. Franky was useless like always. Usopp took off a chunk. Sanji died, Nami died. Luffy took off a chunk.
For about 20 minutes I was just spamming Chopper's rumble ball then using Robin to heal him if needed. Eventually Robin was knocked out then brought Chopper out again. Used Rumble Ball when health was low and he turned into Monster Chopper and OHKO'D Nightmare Luffy (and this was on Hard mode too. So much win.)
So I'm guessing it's something like
- Spam Rumble Balls with Chopper, have everyone else KO'D and then use it again when your health is low. It's random since I got it only once ever.
UC2 is more easier as you just have to use 3 Rumble Balls without dying.
Okay, gotcha. I knew Sogeking was one of Usopp's specials, but, for whatever reason, thought you meant you could just use him without having to use SP.
I'll have to try that Nightmare Luffy thing…