Chapter 203: The Invisible Sword...
Ren's smile did not fade as the red stitch on the window moved fast, forming into English letters, into another binding vow.
3. "Ephemeral Edge".
Vow:
"The Sword shall fade within an hour — its edge never lingers."
Effect:
Sword threads dissolve after one hour no matter what, making them impermanent. In exchange, their edge is vastly sharper than Spider or base Stitch, formed not as smooth lines but as curved, jagged, abrasive edges that chew through defences.
Cost:
No permanence. The sword cannot exist longer than an hour, no matter how much cursed energy Ren feeds into it.
"Yeah, much better than the last one."
Ren leaned closer to the window, watching the crimson letters pulse faintly.
"I'm losing something I don't need — permanence. The sword part of Red Stitch doesn't have to last long. It's not a tool; it's a weapon. It's born to cut, not endure. Just like a blade should be used — simple and brutal. I'm throwing away something useless for something far greater."
He chuckled softly. "This is kind of a perfect binding vow, plus it also sounds much cooler than the last vow, and not to mention the curved jagged edges are something which will be able to cut most things… but I can take this one step above…"
The red letters on the window stirred again, shifting, rearranging—another vow taking shape.
4. "The Self-Sharpening Fang".
Vow:
"The harder the resistance, the keener the blade. Every obstacle hones the sword."
Effect:
Whenever Sword encounters something it cannot cut, it automatically refines itself — becoming sharper and more lethal until it slices through. This gives Sword the theoretical ability to cut through anything.
Cost:
Each refinement eats into the time limit of Vow 3. The one-hour maximum bleeds away, shrinking to minutes, seconds, or even moments if the resistance is extreme. The sharper the sword becomes, the faster it fades.
'The 4th vow… Self-sharpening is truly genius and also something copied right out of Sukuna's book. His Cleave also gets sharper depending on the toughness of his opponent. I don't know how he does it, but this is how I will do it…'
He paced, his tone low, words tumbling out faster.
'The stronger the object the sword tries to cut, the sharper the sword becomes on the spot, instinctively! Together, Vow 3 and 4 make Sword like a cursed energy guillotine which gets sharper... But the cost… the time limit. The sword strings already have a one-hour lifespan because of the 3rd vow. Now, that timer burns away even faster…'
Ren grinned. 'But that does not matter if I can simply cut through something with one sword string; then I don't need multiple of them… It's brutal… clinical… and the 3rd and 4th vows also connect beautifully. The 3rd made a fake weakness — a time limit. But the 4th abuses that weakness, turns it into a weapon. The shorter the time, the faster it sharpens. A self-devouring system. A perfect contradiction — weakness feeding strength.'
His eyes widened, blood rushing with excitement. 'This… This might be my most optimal binding vow yet; perfection between two binding vows creates the true power... but it's not done yet! I can go one step further… one more binding vow…'
He didn't even notice the faint creak of his apartment door opening or the quiet click as it shut…
Someone had entered.
But Ren's mind was too deep — caught in what could only be described as a cursed energy trance, that rare 'flow state' where the impossible could be reasoned into form, so Ren didn't pay attention to anything and kept thinking because even he knew right now he was on the precipice of the peak...
The red threads moved faster on the window now, glowing faintly in the cold wind seeping into the room. His fingers twitched as he focused.
And then — the window flashed. English letters formed, made of writhing red thread.
Ren's smile widened even more.
5. "Invisible Blade".
Vow:
"I vow to bind this blade to absence: let no eye, no sense, no strand of cursed energy perceive it—not even my own; let its threads, when called, conjoin and pool their timers and sharpening into a single, prolonged edge."
Effect:
The threads may merge into one another, pooling their timers together. Two threads become one with doubled duration, five threads become one with quintuple duration, and so on. Merging multiplies both time and sharpening potential from Vows 3 and 4.
Cost:
Ren forfeits all perception of Sword — he cannot see, hear, or feel the threads with cursed energy.
"Hahahahaha, this is it! I did it! Ha, this is perfection. The cost is also a strength!" He threw his hands up, his hair falling into his eyes. For a moment, he looked unhinged — a man who had seen divinity in his own madness.
His thoughts spun wildly.
'The cost itself is making the sword part of the red stitch fully invisible! And the effect is not a boost to power or something like that; no, the effect is just simple addition! It gives me the ability to add my sword threads and merge them together… for something stronger!'
Ren's breath came in short bursts as his mind raced. His thoughts thundered in rhythm with the cursed energy flooding the air.
'Well, the reason the cost is so weak, and it could even be considered a strength, is because of the intention in the wording… of the binding vow, I am not just simply adding the powers of all the sword strings; no, that would take a much larger cost. What I am doing is simply merging them… And what does that merging do? It is up to my interpretation! because that's how binding vows with oneself work! You decide on the contract, the effect, and the cost hahahahaha!'
'What I am merging is the time limiter of each sword string! What does that mean in simple words…?'
He raised his hand as if counting invisible equations midair.
Result: One thread = one hour, extremely sharp.
Merged five threads = five hours; the edge becomes terrifyingly refined.
Merged ten threads = ten hours — the ultimate invisible guillotine.
'The sword thread will use its lifetime when trying to cut something it can't cut, though… but if that timer gets longer! Then won't, in theory, the thread also get even sharper!? That means that means! If I can't cut something with one of these sword strings, then I can merge them and then try to cut again. The speed won't change. Nothing won't change really, but the second it touches the thing I was trying to cut, it will go through its lifespan fast, not in 1 hour but in 2 hours, and cut through it… In theory I should be able to cut through anything! if I merged all 10 strings into one! I have out done myself ones again!
Hahahahahaha, this is genuine… I am the smartest man alive!'
Ren actually spoke the last part… "I am the smartest man alive!" he declared, almost breathless with manic triumph.
Ren spun around in place, laughter echoing through his apartment — but then froze.
Because Ren saw Maki standing there in her pyjamas, a pillow in her hand and her eyes wide open, her expression frozen between fear and disbelief.
She looked like she had just walked in on something monstrous—something that shouldn't exist.
The faint moonlight from the window touched her face, highlighting the pale shock written across it.
Ren didn't move. Neither did she.