It's not the darkness receding, or his consciousness returning in waves of splitting headache. It's the stench. The air burns his lungs, and he can feel his skin crawl in a very familiar way. Like when he had spilt a vial of acid on his hand that one time. It's just not his hand now, but he's whole body is itching. It's damp and dark, and once Kell regains his consciousness for long enough to move, he finds out that he's trapped. The walls around him, the floor, all are made of something stinky and squishy. The stench of decay, one smell that he's been overly familiar through the incident with the Heralds, permeates everything here.
He crawls on his hands and knees, weak and nauseous, his head swimming. Tries banging on the walls of his prison, but the only sound he makes is an ugly squelch as his fists go half-way through into the moist, slimy wall.

Kell tries to concentrates on calling fire, but he only manages to form a sizzling spark that dies soon. Not soon enough, so he doesn't notice the rotting, half-dissolved remains in the far end of his prison. The view sends him collapsing on the floor, wheezing with exhaustion, his head pulsating with pain, hand over his mouth, so he won't lose whatever his last meal was to the sight and the stench.

Kell wants to kick at the walls, but can't muster enough strength to do so. That leaves him with only one option. Yell. Yell as loud as he can. Yell and hope that someone comes before he ends like that corpse there. And it won't be the guards coming to mock him.

"Hey! Anyone out there?! Help! I'm trapped inside!"

The utter disgrace of having to shout like that burns no less than the acid in the air and on the walls.