PlayStation All-Stars Battle Royale

I've been watching combo videos on PersonaWorld's youtube channel and the ones for Sly generally start with a smoke bomb (I don't get what this move does). Then you're supposed to sweep, and what ever move you do next will hit but the next one won't. Just try it. All combo's seem to only be practical at a certain stage. In the video, after getting struck by Sly's rolling thunder attack, the opponent is supposed to bounce off a wall, allowing you to combo more. However, even though I use the same stage as in the video, my opponent bounces off the wall in ways that can't be combo'd afterwards. What's a good combo that builds at LEAST half a bar that will always land?

http://www.youtube.com/watch?v=198yWXCd1ww
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No one has the balls to fight these days. It's all about zoning & full screen fireballs

I know his level 1 is cheap and he's really good for running away but does he have a single decent meter building combo?
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No one has the balls to fight these days. It's all about zoning & full screen fireballs

You have to jump cancel in order to get rid of the attack's recovery so you can combo after the opponent hits the wall.
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http://www.youtube.com/user/personaworld

He does have 1 ap combo burst move that I know and use lol.....but it requires the opponent to be blocking and in front of a wall xD