Scruh's closet may look average but in truth it's a portal to the Demon Realm many evil beings have emerged from it including the Prank Lord and Scurse two medium level demons. No person has been through it apart from Scruh himself. No one knows why the demons who emerge hunt after Scruh and try to fight him even if they have no chance of winning, perhaps Scruh angered the demons in some way? That really seems like something he would do.
"I wouldn't go in there if I were you, there are some real weirdos in there" -Scruh