DoubleHush

Meet Alex Knight, a hardworking young man burdened by crushing debt and a bleak future. When his new boss turns his life into a waking nightmare, Alex finds himself trapped in a job he can't escape, his future held hostage by the whims of a tyrant. 
Just when he believes he has one anchor left—his girlfriend's love—a devastating betrayal leaves him utterly broken. 
But then the world changes. The system descends, dragging everyone into a chaotic new reality. Alex becomes the first to sync with it, earning a mysterious title: 
[Apocalypse Baby]
[You have awakened the skill: Exploding Touch]  
[Anything you touch turns into a bomb.]
Armed with a deadly gift, Alex rises from the ashes of his former life to become an unstoppable force in an urban fantasy world where power rules and vengeance drives him forward.

Apocalypse Baby

This was why the undead guide was hurt after his first battle with Alex.

The destruction of the domain had damaged him.

The area of the maze where the domain had formed also gone, and with it, his strength had weakened.

The Death Maze was connected to him.

Its destruction was his destruction.

Alex crossed his arms, watching the Undead Guide's reaction with amusement.

He took a step forward, his voice taking on a teasing edge.

"Though, of course, this is all just an assumption," he continued. "But I bet it's pretty close to the truth, isn't it?"

The Undead Guide's glowing eyes narrowed.

Not because Alex was wrong, but because he was right.

Alex grinned, watching the hesitation flicker across the Guide's face.

"Oh? No rebuttal?" He let out a chuckle.

"Guess I must've hit the mark, huh?"

Despair And Await