Baal

You were exploring a ruined dungeon, legends mention a powerful object has been lost in there for centuries. You were exploring for hours when you noticed an ancient lamp, it looked out of place, made of dark iron and intrigate paterns. Something was writting on its lid in an ancient dialect, that you luckily knew, you read it aloud 'Power too great must never be unbound'. The lamp started to shake and became burning hot then a huge entity emerged from it.