As early as when he first arrived at Tanzaku Town and began preparing his "Plan B," Haruma had considered countless times whether he should devour Orochimaru.
But, after recalling certain key events from the original story, he dismissed the idea. It wasn't because he feared triggering a butterfly effect, but rather because consuming Orochimaru at this stage would bring little benefit, and, in fact, cause him a great amount of loss.
Orochimaru, after all, was a genius with no special kekkei genkai. Most of the ninjutsu he possessed were already techniques Haruma could obtain from the Third Hokage. Among Orochimaru's arsenal, there was only one thing Haruma truly desired. Edo Tensei, the Impure World Reincarnation.
By devouring Hiruzen alone, Haruma would inherit not just Edo Tensei but also a far greater collection of jutsu, since the Professor of Ninjutsu had mastered nearly every technique in Konoha's history. Orochimaru, on the other hand, lacked access to the Sealed Book and had merely stolen a handful of forbidden techniques, including Edo Tensei and the Eight Branches Technique.
Thus, absorbing Orochimaru right now would only result in redundant abilities and what would he lose by doing so? The cloning experiments? Irrelevant. The perfected Edo Tensei of the Fourth Shinobi War? Perhaps. But in truth, whether it was the "flawed" or "perfected" version, it made no difference to Haruma. As long as he consumed Orochimaru's soul, every memory and every refinement would become his.
Yet, there was one undeniable fact, the perfected Edo Tensei set into motion countless pivotal events.
Without it, Kabuto would never rise to become a key villain of the Fourth Ninja War.
Black Zetsu, the manipulator of a thousand years, would not have been able to direct Kabuto into reviving Madara's corpse.
Without Orochimaru's tutelage, Sasuke Uchiha, Indra's final reincarnation, would never grow at the pace that he did, likely reaching elite jonin levels of strength.
All of these consequences, the intricate chain reactions, would vanish if Haruma decided not to consume Orochimaru. That, more than anything else, was the greatest factor when making his decision.
By sparing Orochimaru, and letting him nurture Kabuto and Sasuke, Haruma could one day devour them all at the peak of their growth, maximizing the feast he would get to enjoy.
Of course, Haruma had already resolved that if he could not extract the Edo Tensei through the Yamanaka clan's Mind Reading Technique, he would kill Orochimaru on the spot, consequences be damned.
Fortunately, Edo Tensei was not a contract-bound summoning jutsu, it required only a sacrifice, some chakra, and a sealing formula to open the gates to the Impure world and drag a soul back into the living world. After rifling through Orochimaru's mind, Haruma now possessed this forbidden technique.
For more than half an hour, Haruma had combed through every single inch of Orochimaru's memories, every meal eaten and every experiment attempted, until he finally found the information he wanted and with that, he pulled back from the mental world.
Using his sharingan once more, Haruma flooded Orochimaru with more and more Yin chakra. At this stage, Orochimaru was powerless to resist. His serpentine features slackened, his expression twisting in discomfort before his throat bulged. With a guttural retch, Orochimaru disgorged a sealed storage scroll, slick with mucus.
This scroll was one of the two treasures Haruma had been after, within it were the preserved remains of the previous Hokage, along with samples of the Third and Fourth Kazekage.
Haruma didn't even stoop to touch it, quickly putting on a glove before extending his hand and letting an emerald-green branch sprout from his palm, shaping itself into a wooden hand. It lifted the scroll, encased it in a wooden box, and pulled it neatly into Haruma's grasp.
Swish.
The task complete, Haruma dispelled his Adamantine Sealing Chains and vanished in an instant.
Orochimaru and Kabuto, however, were still immobilized by the Four-Limbs Seal. It took all their effort, and no small amount of sweat, to finally break free from it's constraints.
"I survived," Orochimaru panted, his pale face glistening with cold sweat. His snake-like eyes glimmered as he laughed softly to himself. "Sharingan of the Uchiha, Adamantine Sealing Chains of the Uzumaki, the Mind Reading of the Yamanaka and Wood Style. Hehe… Who could have imagined there was such a monster within this world? How long has he been watching to have been able to gather so many techniques?"
His grin twisted, equal parts fascination and dread. "He spared me… Does that mean I still hold some value for him? Or has he grown so confident he no longer bothers to conceal himself?"
Orochimaru's voice grew low and rasping. "Rinnegan leading the Akatsuki and now this masked man wielding both the sharingan and wood release. This world is becoming stranger, darker, more terrifying."
And deep down, Orochimaru felt it, a creeping despair. Once, he had believed the world lay within his grasp. Now he wondered, what use would the sharingan be when facing gods and monsters like these?
Haruma, of course, paid him no mind.
With Edo Tensei and the remains of past Hokage secured, his plan had already reached 99% completion.
Returning briefly to his house, he left a note for Karin, who had gone shopping, before slipping away from Tanzaku Town.
Half an hour later, Haruma stood in a desolate clearing far from prying eyes.
"Wood Release: Wood Clone Jutsu."
Four clones emerged, dispersing in the four cardinal directions, byakugan and mind's eye active, scouring the land.
Meanwhile, the true body raised a home of timber from the earth, stepped inside, and prepared at last for the long-awaited moment, his ascension, the leap over the dragon's gate.