The basement under Kakashi's house was dim, quiet, and filled with a faint hum of chakra from the array of sealing diagrams etched into the stone floor.
Kakashi stood alone, sleeves rolled up, the massive Forbidden Scroll from Tsunade lying open beside him. His Sharingan glowed faintly, scanning lines of old Senju calligraphy and complex sealing formulas.
He exhaled and leaned against the stone table.
"I forgot something," he muttered to himself. His mind turned to the Orochimaru he had recently revived.
The soul was obedient, calmer, more of a remnant than the full serpent sage, but still sharp, intelligent… and useful. More importantly, Orochimaru knew Edo Tensei better than anyone alive.
A glint of opportunity passed through Kakashi's eyes.
He reached into a drawer, pulled out a small summoning scroll, and summoned a messenger serpent. He quickly wrote a short message and whispered, "Take this to Anko."
The snake coiled the scroll with its body, gave a respectful nod, and vanished in a puff of smoke.
Not long after, the basement door opened with a low creak, and Anko stepped in, dragging the tall, pale figure of Orochimaru behind her.
"Be a good boy, or I'll shove a kunai in your ribs," Anko muttered, half-smirking.
Orochimaru shot her a withering side glance. "Still as charming as ever, Anko-chan," he said in that sickeningly smooth tone, though the twitch of his mouth revealed bitter amusement. He ignored her after that and turned his full attention to Kakashi.
"You called for me, Kakashi-sama?" he asked politely, tilting his head ever so slightly.
"I need to learn Edo Tensei." Kakashi folded his arms and nodded.
"I could perform it for you if you wish" Orochimaru blinked once.
"No," Kakashi cut him off, voice calm but firm. "I want to learn it myself. I need to understand every layer. You'll explain, I'll learn."
"Ah… how nostalgic. Teaching once again. Very well." The snake sage smirked, his eyes glinting.
"I brought some test subjects. Rogue ninja corpses from old missions, nothing that'll raise alarms." The door opened again, and Tsunade stepped in, holding a tray of sealed samples.
She placed the tray down, gave Kakashi a small smile, and left the two men to their work.
Orochimaru crouched by the scroll and began unsealing the formulas with an expert hand.
"The process, as you likely know, requires a sacrificed body and a DNA sample from the one you wish to revive," he began.
"The soul is summoned from the Pure World, bound into the sacrificial vessel using a layered seal"
"And the body… degenerates unless stabilized, right?" Kakashi was already copying the inscriptions to use them with his Formula Reconstruction technique.
"Exactly. That's why my version used binding talismans and reinforced anchors. But your chakra… your seal network is more flexible."
Orochimaru spoke fluently, methodically, even as Kakashi began forming hand seals. Within two hours, the room was thick with spiritual chakra as test after test progressed.
Kakashi's fingers flew, his Sharingan absorbing every detail Orochimaru revealed. The Soul Anchor formula was modified, the summoning circles were refined, and the sacrifice method… well, Kakashi had his own.
He summoned a mass of white spore clones, miniature blank Zetsu bodies created through the Genesis Seal. Their pale skin and empty eyes made them look eerie, but they moved without resistance, kneeling before Kakashi.
"You made clones to serve as vessels?" Orochimaru's eyes widened, a rare moment of awe on his usually smug face.
"They're biologically stable. Grown from chakra, but adaptable to soul tethering." Kakashi nodded.
"Fascinating… They respond like perfect blank canvases." Orochimaru touched one of the clones, and the skin twitched under his finger.
"Much better than the wood-style husks I experimented with. How did you manage this?" He said, awe could be heard in his voice.
"I used a special technique to obtain these abilities," Kakashi said casually.
"You've truly gone beyond me, Kakashi-sama. A new era of jutsu indeed." Orochimaru gave a slow, delighted clap.
The two began a test revival. Kakashi placed a drop of blood from one of the rogue ninjas onto the spore clone, activated the seal array, and performed the jutsu. The floor lit up in blue, red, and black, swirling together in a beautiful storm of light.
A moment later, the ninja emerged, alive in form, but still semi-bound.
"He's functional," Kakashi muttered, inspecting the result. "But…"
"But the soul is unstable," Orochimaru said, already seeing the problem. "It didn't transfer properly. The clone lacks the natural soul tether."
"So we need something deeper. Something to link the soul to the blank body permanently." Kakashi's eyes narrowed.
He turned back to the Forbidden Scroll, flipping past pages until he reached the notes bound with red string, personal notes. At the bottom, scratched with quick handwriting, were seal formulas even more complex than the rest.
"Tobirama's personal research," Kakashi said, holding up the scroll. "Second Hokage's secret work."
Orochimaru's eyes lit up like a child seeing a candy store. "You mean these are Tobirama's private theories?! Not the watered-down versions in the Hokage library?"
"These never left the Senju archives. Tsunade brought them." Kakashi smirked.
"Kakashi-sama… just seeing these notes… this-this is how I first conceived my Living Corpse Reincarnation technique. From just a glimpse of his writing in the Hokage records." Orochimaru hovered closer, reverently reaching out to trace the scroll with his fingers.
He looked as if he'd seen the most beautiful woman in the world.
"Calm down, you're drooling," Kakashi muttered, rolling his eyes.
"Forgive me. It's just… this man's mind was like none other. Even now, I learn from him." Orochimaru wiped his mouth with a sleeve and gave a sheepish chuckle.
Kakashi crouched down beside him. "Then help me decode these. If we combine what you know with this, we'll crack the soul-body link problem."
"Gladly," Orochimaru said, excitement still in his voice.
They worked for another two hours, poring over the scrolls, redrawing formulas, and refining the chakra patterns. Kakashi weaved his Formula Reconstruction Technique into the Edo framework, merging stabilizing lines from the Soul Binding Seal he had once used on Orochimaru's fragment.
Finally, a new seal was born: a five-layered spiraling matrix that could anchor a soul into a genetically adaptable body without degrading it. A perfected form of Edo Tensei.
"Let's test it again," Kakashi said, eyes glowing with intensity.
He summoned another spore clone, used DNA from a different test corpse, and activated the new seal.
A burst of smoke exploded, and a revived ninja emerged, blinking in confusion, completely restored… and alive in every sense of the word.
"He… he's stable," Kakashi said in amazement. "No cracks. No chakra bleeding. No decay."
"This isn't Edo Tensei anymore… this is Rebirth without Rot. The body is alive, and it's not a puppet, not an undead either." Orochimaru stared at the man, awe creeping into his voice.
"I think we've done it." Kakashi sat back against the wall, exhausted but proud.
"Kakashi-sama, with this… you'll be able to bring back Nawaki. And anyone else. Perfectly." Orochimaru gave a deep noble bow.
Kakashi closed his eyes for a moment, thinking of Nawaki… of Kurenai's father… of Sasuke's parents.