Ok, well sorry for not being an expert on chinese architecture. I promise I'll work on that.
Anyway, there's still no reason to believe that it must be Riku he's talking to. The way I see it, he's probably just talking to one of the characters from Mulan.
An unknown obviously came in and interfered with Beast's world, and we can see from some of the shots that the unknown has appeared in Mulan's and Hercules' worlds too. So, it seems like this unknown is going to appear periodically in the game, causing a lil bit of trouble in each world that Sora visits. I'd say he's probably talking to character from Mulan, wondering what kinda trouble the unknown has caused in this world.