However, it doesn't appear to like the cards that came with the BlayRouzer. Which is kinda odd because the BlayRouzer will take the cards from the ChaliceRouzer. xD
The BlayRouzer is supposed to be able to do any of the four Rider's cards, whereas the other three only do that respective Rider's cards. If you look carefully there are little symbols on almost every card that actually tell what reader they can be read in.
Now this is just a theory...but when you Rouze a Chalice, Garren or Leangle card in the BlayRouzer, does it make a different sound than in their Rouzers? I heard about this, but haven't tested it myself.
I beleive the King Rouser reconizes them all. Although if it's not a Spade, all you'll hear is something like "Dai Card" if it's a Diamond, or "Heart Card" if it's a Heart & so on. Don't think you can do the combo attacks of the other riders, but you can do the 2 Pair, 3 Card, 4 Card, Straight Flush, ect. attacks.
Each Rouser will read the cards from that Rider whether it's the Sealed cards or the Generic ones. If it's a Generic card though, the Rouser will usually say something different than normal like "Henshin" or "Leangle" (as in the case of Leangle's Rouser) or something to that effect.
There is a listing of what the cards say in each Rouser on a website...but I don't have the link, since I'm at work right now.