Behind the mystery door, A contest by @onceuponatime

A man with an unquenching thirst for mysteries sees a old rusty door at a distance. Looked like it had not been opened for centuries. His quench for mystery loured him to the door. A strange voice inside his head said come in don't be afraid. He starred at it for a while, he could feel that the door hid something within. He was not scared of course he had the batman buckle on that day.
Without waiting any longer he opened the door. At first it seemed very dark inside and he couldn't see a thing. He used his torchlight but the light never got through. He was surprised to see this. He took a daring step into the darkness and walked forward. The room seemed vast and never ending, so he kept on walking and saw a shimmering magical portal ahead.
When he walked through the portal he ended up in strange place. A place he had seen in his dreams the night before.

He had reached the Underworld, A place where no mortal has stepped foot before. You could hear the souls screaming in agony, he looked back and the portal he came through was gone and the only way was to move forward.He took a deep breath and walked ahead. There were skeletons hanging on both the sides of the road leading to center of the city. At a distance he saw a magnificent throne made of demon skulls and on it was a humongous beast like being starring right at him.

He had a feeling that he had been here before. The beast gets up from his throne and walks towards @onceuponatime. He expected a fight. He thought he was going to die, the regret of not auctioning the batman belt made him furious and shouted at the beast, " What do you want you hideous monster ?"
The beast walks up to him and bows down, handing him over his demonic sword of death. And says, " I have waited for this moment for too long now, the time has come for you to rule the underworld now" and disappears into thin air.