Secret - Moels
Go to the dieing farm and walk into the house. Talk to the girl insid she will give you a quest kill 50 moles and she will give 2000exp.
Free Devil Costumes
Stock up on plenty of Health pots and everything else that you need. Run through the quick maze of hell, and along the way, you should find a chest with atleast 1 Devil in it. It re-spawns every Hour. So, you have to wait.