Me and my demon. (Multiverse fanfic)

The cave 2.1

Jack shoots up from his sitting position, breathing heavily and coughing.

He takes a moment, and looks around warily, before feeling pain in his stomach.

He bent over, groaning in pain, before leaning over to the side and vomiting profusely.

"Ugh," he slowly reaches to the wall to stabilize himself. "Fuck."

He slowly stands, leaning against the rocky wall for support.

"Where am I?" Jack asked himself, feeling around to see if that would give him any clues. He could feel the cold wetness around him.

"A cave?" He still was unable to see anything, but it sure felt that way.

"Are you still here?" Jack said internally, waiting for a response.

"Of course." Jack sighed in relief.

"Any idea where we are?" Jack asked the internal demon.

"A cave."

"Really." Jack thought, rolling his eyes.

Jack took a moment to gather his bearings, and it all came rushing back. Angel's takeover, Violet's death, the planet exploding, all of it.

Not being able to handle all of the grief, Jack leaned against the cave wall and slid down to a seat, resting his head on his knees. "Hey, you okay?" Shadow asked, concerned for Jack.

"...No." Jack painfully replied, Shadow sighed in empathy, and took control from Jack, who did not attempt to resist.

The darkness of the cave congealed on Jack, swirling around his body and transforming him.

His body shifted from skin to a solid black substance, making him grow in size. His hands grew with muscle, and claws formed at his fingertips. He became more muscular, his body liquifying partly to form his armor.

His mouth broke out into a crooked smile, the darkness turning the teeth into jagged fangs. His eyes became fully red, with no iris or pupil. His head emitted black smoke, a side-effect from never forming correctly.

Jack was no more.

Now he was Shadow.

He expanded his senses and began mapping his way through the cave. He slowly walked forward, having found his way.

He walked along the cave tunnel, finding a fork off from the main tunnel. Upon closer examination, he found a small totem within.

"Curious," Shadow said, examining the crudely made totem.

"Is it demon work?" Jack asked, his voice inside Shadow's mind.

"Not one that I know," Shadow said, standing from his crouching position. He turned and made his way back out the side tunnel.

Continuing his walk, he soon came to a familiar sensation.

"There are... things ahead," Shadow said, freezing in place.

"Things? Not human?" Jack asked back. "No. Definitely not." Shadow confirmed and began walking forward again. This time more cautiously.

He came to a room's entrance and stood in front of it.

There, several green creatures flinched back in surprise. Shadow just stood motionless.

We're these the natural organisms of this place? If so, no wonder that they would be surprised. Shadow thought as the green creatures hesitantly approached.