To start off the discussion, I'll mention my consistent personal experience. Thieves have a smoke screen they can throw down that, among other things, causes projectiles to cause blinding when passing through. That meant I could combo with myself dozens of times per battle, and it was quite significant. Like huge. Very neat game play mechanic and insanely useful.
Other than that I have very little idea what was going on or what the effects were. I combo'd a lot with a guardian party member when he would put done some sort of bubble, but I don't know what the bubble's effect was or what the combo effect was.
What were your experiences?