Update: Since the release of Patch 3-12-18, the creatures now move properly but the gear requirements are still the same.
Chillin on some Dark and Light farming the fire cave boss Bel'xahl, a powerful demon residing at the heart of The Scalding Abyss, the Lord of Elemental Fire and protector of the Smoldering Workbench.
The Scalding Abyss is a beautiful landscape that has been a bit underrated. Takes about 25 mins to go down and kill the boss. The Abyss is perfect for farming coal if you need some to craft a few diamonds. So stay out of the fire, or you will get burned.