short story. the empior drank non-pure water and gotten ill. then his (i think spirit) came out and tunred into the jade oni. when you defeat jade oni, he is in bad heaven and empior's normal spirit comes back and is alive.
they grow to cooler stuff in the story each world. wizard city has least eximent. dragonsypre has most eximent. grizzleheim, idk, grows from boring at first to cool.