1. Depends on the boss. Ao has some of the best fights in the series and allows for some really cool strategies, Sen's are pretty easy with certain notable exceptions and are definitely more tank-y. I wouldn't discount The 3rd's bosses in the challenge department either, and not just in the 'it has how much HP?!' category. Chapter 3, I'm looking at you. :angry: 2. Yes, there are story reason for it. Basically, they're the ones assigned to the Crossbell Police's new division (each for their own reasons) and the story is all about their journey from glorified publicity stunt to heroes. The other playable characters aren't members of the team and have their own jobs so they aren't permanent. It's nice having the core cast available from the start and spending the entire game with them (Randy and Tio are a gift that keeps on giving) and all the other playable characters are still there, just as NPCs until it's time for them to join up and fight.