Weird sprite arrangement?

So, I'm trying to make a sprite hack of Kirby's Dream Land (which clearly has never been done before, and I'm starting to see why), but so far, the sprites are mixed in with the games code in such a way that makes custom sprites seem almost impossible. 

The same situation happens with YY-CHR, the only helpful thing it has is that it can re-arrange the tiles, but still can't tell apart sprites from game data.
I'm dead in the water, but maybe someone out there knows what's really happening right here?