Cross Marian walked into the garganta in the soul society. He was making a trip to get back to Hueco Mundo due to not being needed in Soul Society no longer.

"Gosh, looks like we're not needed" He thought to himself as he twirled the gun on his finger. He took a step inside the garganta and it immediately shut behind him, without his command.

"What's going on?" He asked. He was trapped within the world of Garganta, the world of Emptiness and Nothingness.

"Cross Marian, I need your body to live on" A voice trailed through. A blotch of purple smoke appeared in front of Cross. Forming in the smoke was a young man, it was the zanpakto Mugen. He had disappeared as well shortly after giving more of his power to Lee for his transformation.

Cross looked at him with a blank look on his face. He still twirled the gun on his finger. "And why does it have to be me?" He asked. He looked at Mugen closely and figured it wasn't an illusion.

"Because you have the most spiritual pressure out of the ones that I wanted" He said.

"And who were they?" He asked.

"Lavi, Suzaku Minamoto" He said. "I wanted the body of the two of them, but I could never rebel against them during that time, thanks to Lee, I was able to escape that wretched world."

"Well, i'm glad you were able to escape, but, just because i'm here, doesn't mean anything" Cross said. He held both guns together as they formed his zanpakto. "If you chose to fight, i'm not holding back" He said.

Mugen chuckled as he looked at him. "If we were to fight, I would win" He said, smugly. He held his zanpakto in his left hand behind his back, purple smoke forming around it. "I have you know that I am a master of illusions and I can easily kill you and make it seem like you killed me, just simple as that, if I wanted to that is"
He started to laugh a bit, but Cross was one step ahead and appeared behind him and kicked him in the back, sending him downward into the lower parts of the Garganta, the mysterious parts nobody has ever seen before.

Cross and Mugen ventured further down into the inner world of the Garganta. It resembled the human world, but the people there, were lifeless, almost as if they had died and been preserved by the Garganta itself.
"What's this?" Cross asked as he stumbled back. He looked around, frightened by the black look in there eyes, almost as if they were staring back at you, with lifeless eyes.
Mugen stood in the center and laughed loudly. He had his arms crossed as he looked at Cross.
"These are people who have had the unfortunate fate of falling into a garganta" He said.