Cadash is apparently the name of the castle/kingdom of Baarogue.
THAT'S RIGHT! I AM
THE KING OF DEVIL,
BAAROGUE!
As for "quarter eater," it only is if you rush into an area without treating it methodically, or are unprepared. While there is plenty to "surprise" you, if you know how to manage enemies before they become threats, you can punch your way through. I'm not an expert (nor have I 1CC'd the game!) but I typically get to the plant world or graveyard on one credit.