The ground between them ceased to exist. One moment they were separated by a hundred meters, the next their fists connected with power that rewrote local physics. The shockwave flattened everything in a kilometer radius—trees, rocks, hills. All of it simply gone.
Fenn's massive fist caught Rimuru in the ribs. Rimuru twisted with the impact, using the momentum to drive his knee into Fenn's jaw. They separated, circled, clashed again.
He's fast, Rimuru thought, blocking a strike that would have decapitated him. Too fast for something that size. And the power behind each hit—
Another punch. Rimuru caught it, felt his arm creak under the pressure, redirected it into a throw that sent Fenn tumbling. The giant recovered mid-air, landed in a crouch that cratered the earth.
—it's like fighting the sun compressed into a body. And it seems resistance skills aren't as effective when fighting against people of our level. His attacks hurt, too. What a blunder.
Fenn charged forward, his massive bulk blurring with speed that far exceeded anything else's. His fist came from the left. Rimuru blocked. Another from the right. Blocked. A knee to the stomach—Rimuru twisted, took it on his hip instead, felt something crack anyway.
His martial arts, Fenn thought with genuine delight. Its essence is 'flow.' They're exquisite. Each counter flows into the next like water.
He swept Rimuru's legs. The demon lord flipped backward, landed on his hands, kicked upward. His heel caught Fenn under the chin with an impact that sent the giant stumbling back three steps.
But he's smaller. Lighter. Every clash costs him more than it costs me. Time and attrition are on my side.
They clashed again. Fist against palm. Elbow against forearm. Knee against knee. A brutal exchange of strikes and blocks that happened too fast for anyone else to follow. A thousand hits in a split second, and neither gave ground.
Then Fenn's massive hand closed around Rimuru's wrist.
Got you.
He yanked Rimuru forward, drove his other fist into the demon lord's face. Rimuru's head snapped back, and before he could recover, Fenn spun, using Rimuru's own body as a weapon to slam him into the ground.
The impact created a crater within a crater.
He's stronger, Rimuru realized, pain shooting through every nerve. In a straight contest of brute force, I lose. But—
"Spatium."
He rolled with the next strike, came up with the void-blade already forming. Fenn jerked back, the blade passing so close to his throat that it cut several strands of his green hair.
—I don't need to be stronger. I just need to be better.
They separated, breathing hard despite neither truly needing air. The pause stretched for three seconds. Five. Ten.
"You're really good," Fenn said, a genuine smile on his face. It wasn't a cruel or mocking smile. Just... happy. "Really good. It's been so long since I've fought someone who could actually make me work for it."
Rimuru wiped dust from his mouth, his expression unreadable. "You sound like you're enjoying this."
"I most definitely am!" Fenn laughed, spreading his arms. "Can you blame me? For so long in a seal, nothing but darkness and silence, and then this—a worthy opponent, an actual challenge. This is what I live for!"
"Hmm, that's sad," Rimuru said quietly.
Fenn's smile didn't fade, but his eyes did narrow. "Sad? I'm finally free—even if just for a moment—fighting at full intensity against someone who can survive it. What's sad about that?"
"I don't know." Rimuru's amber eyes were strange. "You've been sealed so long that you don't even have anything to fight for. All you have left is the fight itself. As well as the violence and the thrill that comes with."
"And you're different?" Fenn asked, just curious.
"Yeah." Rimuru's grip tightened on the void-blade. "I know exactly what I'm fighting for. Until then, no one in this world or any other will be able to stop the monster I'm willing to become."
Fenn's smile widened. "I see it. I get it. That look in your eyes... you're not fighting because you want to. And that makes you a little scary."
"Eh? Well, that's good, then," Rimuru said. "Be terrified."
"Oh, I'm not." Fenn settled back into a combat stance. "I'm excited."
Then they went back into fighting.
This time Rimuru didn't meet Fenn's charge head-on. He flowed around it. Fenn twisted, caught the Spatium blade on his forearm—the only part of his body reinforced enough to survive contact—and drove his other fist toward Rimuru's chest.
Too obvious.
Rimuru was suddenly gone, appearing behind Fenn, blade aimed for the spine. Fenn spun impossibly fast for his size, his elbow catching Rimuru in the temple. It seemed like stars exploded across Rimuru's vision, but he used the momentum to roll away, avoiding the follow-up that would have pulverized his head.
His power output is ridiculous, Rimuru thought, shaking off the disorientation. Even restricted, he's operating on a scale I've rarely encountered. If this were his true body—
He didn't let himself finish that thought. It didn't matter. This was what he had to deal with now.
Fenn pursued him, his massive strides eating ground. He threw a punch that Rimuru barely dodged, and the air displacement alone was enough to wound Rimuru's cheek. Another attack, this one a palm thrust aimed at the center mass. Rimuru brought up the Spatium blade horizontally, using it as a shield.
The blade absorbed the impact, but Rimuru still felt the residual pressure drive him backward.
He's adapting, Fenn noted with satisfaction. Each clash, he learns and adjusts. He compensates for the difference in our raw power with technique and creativity.
He pressed the advantage, unleashing a combination that would have killed lesser beings a dozen times over. Fists, elbows, knees, headbutts—every part of his giant body became a weapon. Rimuru responded to each strike with blade or redirect or evasion, but the cumulative damage was mounting.
But adaptation only goes so far. Eventually, the gap in power becomes insurmountable. Eventually—
Rimuru's blade caught him across the chest.
Just a graze. Just the barest contact. But where it touched, Fenn's flesh simply ceased. A thin line of absolute nothing carved across his torso. Fenn looked down at it, then back at Rimuru. His smile never wavered.
"That tickled."
"You are a horrible liar," Rimuru said, noting how Fenn's reflexes had opted to protect that area. "It hurt. And you know if I land a clean hit—"
"I'll be a goner," Fenn interrupted. "Yes. That's what makes this fun."
The essence of Spatium was Uriel. The ultimate skill Lord of Vows had a severance series due to its law and spatial management authorities. Spatium operated on these principles and further coated with Rimuru's Lord Ambition, then finally imbued with a thin layer of the effects of Beelzebuth. That was what made it so devastatingly potent, with unrivalled severance and absorption powers.
Rimuru and Fenn clashed again, and this time it was Fenn who changed tactics. His body suddenly became fluid, martial arts that shouldn't work for someone his size flowing with devastating technical precision. A sweep, a throw, a joint lock—Rimuru found himself caught, his arm suddenly broken at an angle that shouldn't be possible.
Martial superiority, Fenn thought, applying pressure. He has the better adaptability, yes, but I have the experience. I've forgotten more techniques than he's learned.
Rimuru's shoulder dislocated with a wet pop. He didn't scream. Didn't even flinch. He just looked at Fenn with those unsettling amber eyes.
"You're not going to beg?" Fenn asked, genuinely curious.
"Heh. Asshole, why would I?" Rimuru's free hand came up, fingers splayed.
Energy erupted from his palm—a pulse that severed connections rather than an attack. The grip on his arm disappeared as the space between them became meaningless. Rimuru rolled away, his shoulder snapping back into place with a sickening crunch.
Raphael?
<
In other words, trade hits.
<
They circled each other around a battlefield that was reduced to nothing more than a wasteland of craters and spatial distortions.
"You know," Fenn said conversationally, "I was really hoping you'd be more participative than this. But you're holding back."
"Am I? What makes you think so?" Rimuru's tone was flat.
"Oh, definitely." Fenn grinned, wiping blood from the corner of his mouth. "I can feel it. You've got something else tucked away. Some final ace. And you're too scared to use it because..." He tilted his head mockingly. "What? Worried about losing control? Becoming like me?"
"You really do talk too much."
"And you're too uptight," Fenn shot back. "Seriously, loosen up. We're having a death match here. This is supposed to be fun."
"Fun? Yes, of course we're having fun. Matter of fact, I'm having the best time of my life!" Rimuru's laugh was loud, boisterous, yet very obviously and painfully sarcastic.
"Now you're getting it!" Fenn's smile widened, completely missing—or ignoring—the sarcasm. "See, this is what I love about violence. No pretense. No lies. Just pure, honest intent. You want to kill me. I want to kill you. Beautiful in its simplicity, don't you agree?"
"Nah, you're just sick in the head."
"Says the demon lord who just killed a god," Fenn pointed out cheerfully. "What was his name again? Keith? You didn't just kill him—you ate him. Condemned him to torment, too. And you call me insane?"
Rimuru's expression didn't change. "Should I say 'oops'? He had it coming, cuh."
"Oh, absolutely!" Fenn agreed enthusiastically. "No argument there. I'm just saying, maybe we're not so different after all."
"We're nothing alike."
"If you say so." Fenn's tone was dismissive, already losing interest in the conversation.
This time the clash was different. Neither held back. No testing, no probing—just pure, overwhelming violence.
Fenn's fist connected with Rimuru's face. Arms cracked. Rimuru's blade carved through Fenn's shoulder. Flesh ceased. They spun, traded positions, struck again. And again. And again.
He's accepting the hits, Fenn realized with growing excitement. Trading damage deliberately! Each hit costs us both, but he's betting he can outlast me.
Each impact shook the ground. Each clash sent shockwaves that flattened anything still standing.
And he might be right.
Rimuru took a devastating blow to the ribs that caved in his side. He used the momentum to drive his blade through Fenn's thigh. The giant roared and brought both fists down in a hammer blow that drove Rimuru into the earth.
The crater was massive. Rimuru lay at the bottom. Above him, Fenn shot down like a meteor.
Gotta get up, gotta get up, Rimuru forced himself. Get. UP.
He rolled, and Fenn's impact missed by inches. Rimuru charged upward, blade leading, and caught Fenn across the face. The giant's cheek disappeared, along with part of his jaw.
They separated.
"You're... full of surprises," Fenn managed through his half-gone face. It was already regenerating, but slowly as it struggled against the Spatium blade's erasure effect.
"You're stubborn," Rimuru replied, his own body knitting itself back together. Faster than Fenn's.
<
I don't think so.
<<...Reasoning?>>
He'll probably force me into action anyway, like picking up someone as leverage. We can't have that.
<
They charged simultaneously.
The resulting clash was less a fight and more a mutual attempt at annihilation. No technique, no strategy—just two divine beings colliding with everything they had. Fenn's hands tried to tear Rimuru apart. Rimuru's blade tried to erase Fenn completely.
The earth beneath them gave up entirely, opening into a chasm that swallowed them both. They fought in free fall, trading blows as they plummeted into darkness. The impact at the bottom should have killed them both, but it didn't.
They rose from the rubble, circled each other in the newly-formed canyon. Neither of them wanted to stop.
Fenn looked down at him, and despite everything, his grin widened. " You just keep getting back up like some kind of cockroach. I respect that." He cracked his neck.
"Is that supposed to be a compliment?"
"Take it however you want." Fenn shrugged his shoulders. "Point is, you're strong. That's all I really care about."
"You think? Let's finish this, then."
"Now you're talking!" Fenn's power surged again, excited. "Come on, demon lord. Show me what you've really got!"
<
Raphael. The thing we discussed.
<
There's no other way. Just do it.
<<...Understood. Preparing Antithesis.>>
They clashed one final time.
Fenn's power surged to its absolute limit, the seal straining, his manifestation time running out but his strength reaching its peak. Every ounce of his might compressed into a single, devastating strike.
"HERE'S WHERE YOU DIE!"
Rimuru's response was silence.
Inside Beelzebub's Imaginary Space, in the void where nothing should exist, Black Flame and Black Lightning entered a quantum state, then underwent a process so delicate and unstable that it defied every law Rimuru understood about energy and matter.
But he trusted it all to Raphael.
The flames didn't burn. The lightning didn't spark. They existed in superposition, neither one nor the other but something that existed in the space between states.
And then they collapsed into singularity.
Rimuru's eyes began to glow with swirling black and crimson mixed with gold, creating a color that hurt to perceive. Black and crimson lightning crackled on his fist, shredding the space around it.
"What... what are you—" Genuine alarm finally broke through Fenn's violent glee.
"Antithesis."
He crossed the distance between them using Godstep, and appeared in front of Fenn in a way that bypassed space entirely, as though he'd always been there.
"HAH!" The surprised Fenn spared not a moment longer and unleashed his own fist.
The moment the two punches connected, Fenn's attack, as impossibly catastrophic as it was, was immediately subdued. His outstretched arm was blown off, but Rimuru's fist continued, unimpeded, and it dove straight to his chest until it caved in.
The Antithesis's effect didn't explode outward but imploded inward, all its power collapsing into a single point. It didn't add or multiply power—it compounded every ounce of force, making it an exponential power as each recursion was fed back into the next in a loop of escalating destruction with no theoretical upper limit.
Fenn tried to scream, but his lungs were already gone. Tried to regenerate, but the damage was eating through him faster than his power could compensate. Tried to retreat, to disperse, to do anything, but it was no use. The destruction rippled through the giant's body in recursive waves that just kept going.
And Rimuru, caught in the technique's euphoric state, felt clarity. And along with that clarity came a state of looking like something that had forgotten what it meant to be anything other than... destruction.
......
...
...
Rimuru's golden eyes went strange, and his pupils were dilating. An inappropriate and unsettling smile tugged at his lips. It felt good. Too good. Like his brain had been dipped in honey and electricity.
This is... haha... this is insane...
His thoughts scattered and came together, crystal clear yet oddly detached. Time felt malleable.
He looked at Fenn.
Fenn's temporary body, the manifestation created by the summoning contract, shattered. The construct that held him in this world broke apart like glass.
"Huh," Fenn said, his voice oddly calm even as his body began to dissolve. "That's... new. You really are... full of surprises."
Rimuru stood there, that strange smile still on his face, eyes glassy and distant yet somehow piercing. "Hehe... yeah... it's pretty... pretty neat..."
"Strong," Fenn acknowledged as his body became translucent. He wasn't dead—couldn't die, not really, not when his true body was sealed elsewhere. But this manifestation was done. "You're genuinely strong." He grinned even as he faded. "I'll remember you, demon lord. This pain you've given me—it'll stick around in my seal. A nice little souvenir."
Fenn scattered into particles.
"We'll fight again someday," Fenn's voice echoed, already far away. "When I'm really free. When you can fight me at full power. That'll be—"
He was gone.
Rimuru was left alone in the canyon, that drugged smile still plastered on his face. His eyes were unfocused yet hyperaware, staring at where Fenn had been. Then his head tilted wobbly as his senses picked up something else.
Oh... right... the... the flying ones...
A little far from him, thousands of Apostles were still fighting with his friends. The battle hadn't stopped just because he'd been busy dozens of miles away.
Can't have that...
The Spatium blade materialized in his hand again, that streak of absolute black. Rimuru looked at it, giggling softly.
"Hehe... you're so pretty... so... so sharp..."
<
"Raphael, shhhh." Rimuru's smile widened. "We've got... got work to do. The cleanup... yeah... cleanup time..."
He launched himself from the canyon in a burst of speed that shouldn't have been possible in his condition. But the drug-like effect of Antithesis was still thrumming through him, and that euphoria made his exhausted body move like it was weightless.
The first Apostle didn't even see him coming.
So slow... everything's so... so SLOW...
The blade passed through her wings, her torso, her thighs. She ceased in three sections, fragments already dissolved before they hit the ground.
One.
Another Apostle, this one turning toward him with empty eyes and raised blades.
Two... no wait... three? Four? There's so many...
The blade sang and Apostles fell from the sky like burnt flies.
Five six seven eight—
"Hahaha!" Rimuru laughed, the sound high and manic as he carved through the sky. "This is... this is so easy! Why was I even... hehe... why was I worried?"
Nine ten eleven—wait did I count that one already?
An Apostle dove at him from behind. He sensed it and spun, blade extending in an arc that caught three more in its radius.
Twelve thirteen fourteen fifteen—
The battlefield below had gone silent. Soldiers and heroes alike had stopped fighting, staring upward at the impossible show. Rimuru was everywhere, and Apostles that had seemed endless moments ago were disappearing in waves.
So many... there's so... focus, focus, can't miss any...
His thoughts were crystal clear in some moments, completely nonsensical in others. But his body didn't stop.
Twenty... something... lots... definitely lots...
"Got you—!" Rimuru giggled as he caught an Apostle trying to flee. The void-blade extended impossibly long, bridging the distance in an instant. "No running! That's... that's against the rules! You started this... you don't get to... to just leave!"
<
Rimuru couldn't hear Raphael's count. He was lost in the clarity-that-wasn't-clarity, seeing everything and processing nothing, trusting his partner skill to guide his strikes while his conscious mind floated somewhere between euphoria and exhaustion.
The ones over there... yeah... those four... no five... definitely five...
And then he blinked across space—not using teleportation of any kind, but just pure speed that made it look instantaneous. And the blade carved through their formation like it wasn't even there.
So pretty... the way they... they just stop living... like turning off a light... click, gone...
Minutes passed, though Rimuru couldn't tell if it was seconds or hours. Time felt elastic and meaningless. All that mattered was the next target, the next swing, the next click that turned yet another light off.
<
"Come on, come on!" Rimuru's voice was sing-song, almost playful despite the massacre he was conducting. "Where are you hiding? I can... I can see you... all of you... every single one..."
His amber eyes were wide, pupils blown, tracking every movement no human could follow. An Apostle tried to dive into cloud cover. Rimuru followed her, blade leading, and emerged from the other side alone.
<
The last clusters were scattering now, truly fleeing rather than fighting. It didn't matter. Rimuru hunted them down with one by one.
Can't leave... can't let them... they'll hurt... they'll come back and hurt...
<
The final Apostle made it almost to the horizon before Rimuru caught her. The blade extended like a spear, crossing kilometers in a heartbeat, and she simply stopped.
<
Rimuru floated there, high above the battlefield, the blade still extended and dripping with Apostle blood. His chest heaved with breaths he didn't technically need. That smile was still on his face, but his eyes were starting to lose focus.
"All gone..." he said to himself, giggling. "Every single... did I get them all? I think... I think I got them all~"
He turned in the air, scanning the sky with hyperaware senses that were starting to fray at the edges. No more threats. No more enemies. Just smoke and silence and thousands of people below staring up at him.
Job done... I did... I did good, right?
The blade dissolved from his grip.
And that's when the crash hit.
The euphoria drained out of him like water through a sieve, and suddenly Rimuru was just... tired. So unbearably tired.
He fell fast, landing on the scorched earth with yet another explosion while still standing. Then his knees gave out. Not dramatically, though—just a quiet, gradual collapse as his legs finally refused to hold him anymore.
Just for a moment...
His eyes closed.
Around him, silence.
Then—
"Rimuru!"
It was Hajime's voice, strangely sharp with concern that didn't suit his voice. Footsteps thundered across the broken ground. Multiple sets.
"Lord Rimuru!" Tio's voice, closer.
"Rimuru!" Shizuku, breathless.
He heard them all. Noticed them approaching, their worry. Could have responded. Could have forced himself to stand, to reassure them, to keep moving.
But he was so, so tired.
Just... let me pick myself up... just for a second...
Cracks began forming across his face. Hairline fractures spreading from his temples, his cheeks, down his jaw—like porcelain stressed beyond its limits. And from those cracks, golden light began to seep through.
He looked like a hero from a fairy tale. Broken but beautiful. Exhausted but victorious.
"Rimuru!" Hajime reached him first, dropping to his knees beside him. His eye was wide with something that might have been fear. "Hey. HEY. Stay with us. Don't you dare—"
"He's breathing," Shizuku said, her hand going to his neck to check his pulse. For beings like Rimuru, the presence of a pulse wasn't always a factor of life or death, but at this moment, it served to reassure his worried friends. "His pulse is... gods, it's racing..."
"Move aside!" Tio's voice shouted, and the others stepped back instinctively.
Rimuru felt himself being lifted—no, cradled. His head came to rest against something soft and warm. Must've been Tio's chest. Arms wrapped around him, and a hand touched his face with infinite care.
"Well done, my lord," Tio's voice whispered above him, so soft only he could hear. "You've done enough. More than enough."
Yeah... of course...
"Is he...?" Shizuku's expressed her concern.
"He's conscious," Tio said quietly, one hand stroking his hair. "I can feel it. He's aware. He just..." Her voice softened further. "He just needs to rest."
Rimuru could have opened his eyes. Could have spoken. His mind was still processing everything—the battle, the victory, the bone-deep exhaustion. He was aware of Tio's embrace, of the worried voices around him, of the golden light still seeping from the cracks in his face.
But he didn't move.
He just let himself be held.
Just... a little longer... then I'll get up... just a little...
The golden light pulsed once, twice, then began to fade as his body slowly started knitting itself back together.
The euphoria was fading, and with it came the crash—not necessarily painful, just exhausting. Like his entire being had been running at a thousand percent and now the bill was coming due.
Antithesis is so cool...
<<...Technique successful. User survived with minimal consequences. However, repeated use is not recommended. The quantum instability required for activation poses significant risks to cognitive function.>>
Yeah. I could tell. Rimuru's thoughts were clearing, the high fading. I felt like I was flying and drowning at the same time.
He looked up at the distant sky, where he could barely make out the figures of his friends from Tempest watching from a safe distance. They looked like ants from here. Worried ants.