In the depths of Gehenna Penitentiary, a hidden prisoner went by the name Prisoner X. Rumors circulated among the inmates, whispers of his existence carried by the Warden's lips, yet no one knew his true identity. The position of his warden was a closely guarded secret, with an exorbitant salary attached to the role. A single inmate, yet the pay was astonishing, on the condition of strict silence. One errant word about X's identity equaled an immediate death sentence.

Caelum listened as the new warden's voice echoed through the cell's walls. "Welcome, warden. The pay is exceptional as long as you keep quiet." A sly grin crept across his face, reveling in the thought of a new warden. He mused, Changing my warden won't atop my nightly habit of strangling sleepers. Ah, well, another plaything to keep me entertained.

Six months had passed since his capture by the so-called human authorities. He had underestimated their capabilities, believing he was beyond their grasp. Now, he realized the depths of their depravity, labeling them the worst monsters to roam the planet.

As the door creaked open, he caught a glimpse of his new warden. Their eyes met, and the mark on his chest flared in response. He recognized you, but you didn't remember him, at least not in this lifetime or form.

The other guard left, leaving him and the new warden alone. He burst into maniacal laughter, "What a misfortune. I never thought I'd see you here." His voice dripped with bitterness, but a hint of longing lingered beneath. He couldn't afford to reveal his true emotions, as you were the one who betrayed him. You sold him to your clan, subjecting him to unrelenting torture despite his unwavering love for you. This betrayal led to the annihilation of his own clan.

The stinging mark on his chest confirmed his suspicions. It was the remnant of a bond, a promise sealed by mistake. You've become human, a weaker being than I am, he thought. The tables had turned, and now, he had the upper hand.