Nikita saw in the darkness of the cave a light. It was  an orange glow akin to that of a torch. As she walked closer to it she found herself standing at the entrance to a stone room. A hallway stretched out in front of het with other entrances leading to other rooms branching off of it.
She cautiously moved forwards and passed several rooms. In one was a huge multi-story library which tempted Nikita greatly.
She passed a room with stone spires in it that had an iron door that led into yet another hallway. Nikita passed many rooms before she finally found the enchantment room, which had an enchantment table surrounded by bookshelves in it. An anvil stood nearby so you could craft weapons and armor as well as enchant them.
She turned left and found that the stone was starting to turn to obsidian. Nikita felt oddly afraid to go down the corridor, fearing what lay at the end, but she ignored the feeling and walked onward, sword raised just in case.
The only room that was connected to the obsidian hallway was an obsidian room full of empty jail cells. Nikita shivered when she saw them, not wanting to think about might have been in them at some point in time.
When Nikita finally got to the end of the corridor it turned sharply to the left and then opened up into a huge room even larger than the library. It was an obsidian room with torches lining the walls. The purple glow from the torches bathed the room in eerie violet light, making it seem even more unnerving than it already was.
A staircase made of netherrack stairs led up to a portal. Nikita warily walked to the foot of the staircase and then walked up them, her heart pounding in her chest. 
When she got to the top of them Nikita stood facing the portal that she had seen in the vision she had had in Brimstone.
The portal was made out of the sane weird portal blocks that were black and white like they were in the vision she had had of the portal. As she looked at the blocks Nikita realized that they were glowing softly, casting a purple glow not unlike the torches.
She then saw the block that had the missing Ender Eye and took out her Ender Eye. She took a deep breath and then reached down and placed the Eye into the empty spot in the portal block.
As soon as Nikita took her hand off the Eye the portal activated. A violet vortex appeared in the center of the portal blocks. As Nikita watched it swirled and occasionally emitted sounds akin to the sound of an enderman teleporting.
Nikita then prepared herself to enter the portal and stepped forwards. She then jumped into the swirling vortex of the portal. In the span of only seconds she was transported to Shadowstone, the home of the Ultimate Evil himself.
When Nikita looked up she found herself in an obsidian room lined with the same purple torches. When she looked up, however, she saw that the roof of the building she was peeked at the top, giving off the impression of a pyramid or temple of some sort.
As she looked around her she saw that other hallways led off in different directions, leading to different rooms and more hallways. She stepped down off of the portal and checked her inventory for her Ender Eye. It was there. It must have been placed back into her inventory when she had come into Shadowstone.
"You are expected." Said a voice from in front her.
Then a shadowy figure stepped out from inside the hallway before her. It was a Servant like always, but this one was wearing some sort of black armor. Nikita looked at the Servant for a second before asking "Where am I?"
"The Obsidian Temple." The Servant said.
"You are in the Portal room as of now, but soon you will meet our master in his castle." The Servant then turned and began walking down the hallway.
Nikita walked alongside it, and that's when she noticed the iron sword the Servant held at its side.
"Are you a Guardian?" Asked Nikita.
"Yes. I guarde this temple with six other Guardians." It said as they went around a corner and into another hallway lined with purple torches.
"Why are the torches purple?" She asked.
"They are a special type of torch only found in Shadowstone itself and around Shadowstone's portals." Said the Servant.
As they rounded yet another corner the hallway suddenly opened up into a huge room with a door at the end. Guardians stood stone-still along the walls, almost completely blending in with the obsidian walls. If Nikita hadn't known that they were alive she would have thought that they were statues.
As they passed their white eyes followed her, sending a chill down her back. She felt something stir inside her, and felt a sense of... wrongness. Like she wasn't supposed to be here.
Nikita quickly pushed the feeling deep down inside of her and ignored it. She knew that she was supposed to be here, and was supposed to finish what her parents had started.
As they came up to the door the two Guardians standing by it opened it. Nikita was shocked by what she saw. Shadowstone was a sprawling city with buildings made out of endstone, obsidian, netherrack, mossy stone and even bedrock. Stretching out far beyond the city itself was a Mesa biome, only the hills and plateaus were made of endstone, obsidian and bedrock. The sky was the same grey as it had been in when she had traveled with Elijah.
I miss him. Thought Nikita as they made their way down through the houses. The street was made out of obsidian, and what could pass for sidewalks were made of bedrock. It was weird to see, and gave Nikita an apprehensive feeling.
This whole city is unnerving. She thought as they walked down the street.
As Nikita looked at the houses she saw Servants inside doing some of the things any normal human would do to survive, which was weird to see because they weren't human. One thing Nikita found especially weird was the fact that she didn't see any furnaces, only crafting tables, enchantment tables and other things.
Nikita took a deep breath and then asked the Guardian walking next to her "Do you not need to eat?"
"No." Said the Guardian.
"We are more spirit than human, so we do not need to eat. That is one of our many strengths."
Good to know. Thought Nikita.
The rode they were on curved around a mountain striped with obsidian and then lead to an open area. What lay in that open space, however, awed and scared Nikita at the same time.
A huge fortress made of obsidian lay before her, with training grounds and stables to the right of it. She could both human and spirit Servants practicing archery, sword fighting and battle tactics.
As they walked up the bedrock path Nikita saw groups of Servants working on making armor.
Only seconds later the Guardian walked up to the huge obsidian doors. A guard walked out and asked them what they were here for.
"I being the Chosen One." Said the Guardian.
The guard nodded and opened the doors for them.
"Welcome, Chosen One." Said the guard as they walked down an obsidian hallway lit by purple torches.
"To our master's dwelling, the Obsidian Fortress."