Chrono Knight
Normally, he would've sent out his monsters to fight instead of stepping up himself. But this time, Kang Geon planned to hold them back for a bit. After all, he'd decided to test his own power. If his life ever seemed in real danger, he could always call for backup then. Of course, he'd fight with maximum caution for safety.
The enemy might be one rank below him right now, but weakened power and sealed power were entirely different things. Plus, it could have some trump card up its sleeve, like the Curse Devil Gentleman. Something like a sure-kill move designed to obliterate foes of a higher realm.
[No intention of revealing your name, I see. I understand your intent well enough, nameless one. Now die regretting that you ever set foot in this sacred realm.]
"Gauntlet."
[Hm?]
"Gauntlet. That's my name."
With those words, he stepped off into empty air, closing in on the enemy at high speed.
[Looks like you're in the mood for a fight now.]
Chrono Knight raised its massive sword, slicing through the air. A rift tore open in spacetime where the blade passed, and identical copies of Chrono Knight poured out from the gap.
Clones? Illusions? No. They were all real entities, each carrying an SS-grade threat level.
[The ability to summon versions of itself from other timelines. Similar to the powers of the God of Time, isn't it?]
Niara Nephensis appeared at Kang Geon's side in an instant. The other monsters quickly joined, intuitively tying up the feet of the summoned Chrono Knights.
"Thanks."
[Be careful, son.]
He charged at Chrono again. Chrono swung its sword in a wide circle, warping the space around them. It retreated swiftly backward. Kang Geon reached Chrono's original position, but in that moment, he felt his movements slow dramatically. The flow of time in the space approaching the enemy felt altered—about five times slower.
…As expected, its powers work on me.
If Chrono were purely A-grade, its abilities wouldn't have affected him, now purely S-grade, or the effect would've been minimal. But here, they hit him full force. That was the difference between weakened power and sealed power.
[Pathetic. As long as the concept of time exists, you can never defeat me.]
Chrono sneered like that, then wildly slashed at the empty air around itself with its greatsword.
To ordinary viewers, that's how it looked. But Kang Geon could tell what it was even at a glance. A time-manipulating monster. So those swings were definitely carving into the future. In simple terms, if he entered the space it had slashed, the past strike would slam into him. A delayed time attack.
From then on, Chrono toyed with him, mixing time slowdowns and accelerations. Time slowed around Kang Geon, sped up around itself. It exploited this relentlessly, unleashing countless slashes. Of course, none landed. He was a pure physical powerhouse, one who'd raised his threat level through raw body alone. Most attacks barely scratched him; physical blows from a lower rank were just tickles. Occasional magic blasts came too, but he tanked them easily.
In the midst of this torment, midway through, he successfully unleashed a Secret Technique: First Form shockwave. Chrono took it, half its body blown away—but it immediately manipulated time, perfectly restoring itself to its past state. Time-based regeneration.
Realizing ranged attacks weren't working, Chrono would soon close in for a powerful melee strike. That was the opening. When sharing the same space—specifically, when its body or sword made contact—time flows would sync momentarily.
As he thought that, the chance came immediately.
[Your body's disgustingly tough.]
Chrono Knight closed right up to his face in a flash. Even point-blank, the time flow differed. It was finely controlling the manipulated space. But.
[My interest in you has waned, so this farce ends. Now die.]
The moment its greatsword grazed his throat ever so slightly, their time flows synced. He tilted his head to offer his neck while slamming his palm into Chrono's abdomen.
Ah. Naturally, his throat didn't get cut. He'd tensed it fully—no wound at all.
Anyway, with his hand finally on its body, the game was effectively over.
Secret Technique, Second Form: Internal Collapse. A contact-based technique. It collapses the target's internal body structure—and even their soul. By injecting his power into the foe, he disrupts their inner framework. He'd struggled to master it in practice before, but in his current state, it should work smoothly. S-grade power unlocked, after all.
[Why is your neck so—]
"Farewell."
He concentrated all his accumulated power into his palm. Focused energy into each knuckle joint once more, then unleashed it straight into Chrono's innards.
In that instant.
[Wh-what...?]
Chrono's armor crumpled and twisted in places.
[U-ughhh...?]
In less than a second, its entire body collapsed into a grotesque form. Then its body and soul scattered into dust. No time regen this time—soul collapsed too.
With its death, the Chrono Knights the monsters had been fighting vanished too.

■ Chrono Knight
Actual Threat Level:SS-grade
Current (Nerfed) Threat Level:A-grade
Abilities:Time manipulation via greatsword
After Kang Geon and his monsters finished scouting and left the Celestial Realm.
At the edge of the Celestial Realm, the soul-collapsed Chrono Knight slowly regenerated, fully revealing itself.
And then, its body twisted grotesquely once more, its existence rapidly surging to an abnormal height.
This wasn't sudden. Chrono had originally been destined to be born as an SSS-grade monster. The reason it emerged SS-grade was simple: the Ancient Labyrinth's Celestial Realm, where it was born, was too new; it hadn't yet prepared the power to infuse into its body and soul.
Thus, Chrono had temporarily spawned as SS-grade, slowly undergoing existential evolution.
It should've taken years to complete... but detecting its death, the Celestial Realm poured all its power into reviving it, even binding the souls of creatures meant to be born there to Chrono's soul. Analyzing its power and using time acceleration, the evolution finished in mere hours.
In other words, death had accelerated and completed its evolution.
[Gauntlet...]
The newly reborn Chrono opened its eyes, recalling the one who'd killed it. The power that weakened foes. The body immune to attacks. A higher-realm being, much as it hated to admit. Burning with vengeance but wiser after death, Chrono thought coldly, without rash action.
[Can't beat him easily as I am now. In that case...]
Freshly reborn, it instinctively grasped part of its new ability. Killing its past self could erase the present. With this, it could easily kill Gauntlet.
[With my current power, I can pull a past up to five years back... More than enough. Analyzing time flows, Gauntlet hasn't been in this supreme realm even a year. That bizarre power must've come with him from outside.]
In a timeless space. In unified time space. Chrono expanded its unique domain wide. Without hesitation, it unleashed its power full force, beginning to summon Kang Geon from five years ago into its space.
[Gauntlet. I'll erase your past—and your present with it.]
Chrono Knight—no. After existential evolution, now SSS-grade threat, it had shed its old name. It discarded its past name itself, bestowing a new one.
Now, its name was the Devourer of Time, 「Time Eater」.