Dwarves

Like a kid who saw a toy, Sergio looked so excited that he almost jumped from the railing. However, the infinite darkness beneath them made him think twice before doing so.

"It something I found in the dungeon," Nikolai said as he turned off the lights on Alias. "Let's have some light in here." He waved his hand and allowed something other than air into his pocket dimension, which was light.

"Woah!" Sergio watched as the sky, which was black until now, turned into a light shade of red. Nikolai smiled as he also enjoyed the new look of his pocket dimension.

Even though it was constructed by darkness, his dimension was a space in essence. The light came in from Nikolai's location in the real world, so the setting sun was the reason for the red sky.

Nikolai used the darkness of the outside as a portal to get air and light in. His pocket dimension wasn't inside his body but inside of darkness. That's why Nikolai could enter it and leave it as he wished.