I did read Demon Diary--it's one of mikkeneko's favorite series. I always felt a little betrayed by it because the ending didn't match the prologue, but on the whole, it still ranks as the best manwha title I've yet to read, and them's the breaks when you switch writers in the middle of a series.

Remniscient of Petshop of Horrors is reason enough to check something out, in my book. :D I will definitely check out the stuff you linked. I'm still interested in manwha, and free takes away some of the sting of feeling burned by a bad purchase.