DING! Check-in successful. Reward: Eternal Mangekyo Sharingan.
Two blood-red orbs blossomed in Senya's mind.
Staring close, four great windmill blades glimmered within each radiant core.
Eternal Mangekyo Sharingan: evolved from the Mangekyo. Its end-point is the Rinnegan.
"At last."
Though the description was only a single line, it was what he had spent years of sign-ins to obtain.
Excitement rose unbidden.
Even the rice balls before him seemed richer and sweeter.
Seeing the sincere smiles of grandmother and grandson, Senya found himself smiling back.
It had been a long time since he ate with anyone.
...
After dinner, he did not leave right away.
He tagged along as Obito visited neighbors, soaking in the warmth of ordinary life.
Obito happily introduced his new friend to everyone.
When he first arrived in this world, the cruelty of the shinobi world had kept Senya training on a knife's edge, living each day like thin ice.
Now he was about to awaken the Eternal Mangekyo, his strength already at super Kage level.
Time had flown.
"No training tonight."
For once, he chose to slack off.
He chatted about small things, played shogi with the grandpa across the lane, and then, with his signed shogi skill, proceeded to wipe the board.
Old men scratched their heads and questioned reality.
Sometimes this was a fine way to live.
Three hours later, he waved goodbye to Obito.
Back at the Guard Tower, a quick check on his shadow clone, then he fell into the best sleep he had had in ages.
When he woke, dawn had already broken.
After washing up, he flashed to Shikkotsu Forest.
He dared not truly grow lax. Yesterday was a brief change of pace.
He was only super Kage. Far from enough.
One Infinite Tsukuyomi and he would be done.
The fusion for the Eternal Mangekyo would take time.
Once begun, it could not be interrupted. He needed a secluded place.
After a long search, seals set and barriers laid, Senya urged the light within his mind and began fusing the first Eternal eye in a hidden cave.
...
Meanwhile, far underground.
An ancient man with long white hair slowly opened his eyes on a stone throne.
A pitcher plant-like figure of black and white slipped through the earth to his side.
"Zetsu, what did reconnaissance show. After I die, who carries out our plan."
After the Valley of the End, Uchiha Madara had not died, but his wounds were grave.
Without Hashirama's cells he would never have lasted to this day.
Even so, he felt his time was short.
Hashirama's death had only delayed the inevitable.
Before the end, he had arranged his resurrection.
Nagato's role was set.
Only a supervisor remained.
"Lord Madara, I believe Uchiha Obito suits the role."
Zetsu stepped forward and handed over a file.
"Naive. Hot-blooded. A heart for love and friendship. A junior brimming with feeling."
"When such a one meets despair, what force will be born."
Madara finished reading and closed his tired eyes.
"Then him. Make it happen quickly. I do not have long."
Silence returned to the cavern.
...
Two months later.
Shikkotsu Forest.
A massive stone wall burst outward in a rain of fragments.
Within the dust, scarlet Eternal eyes flared with bewitching power.
"Finally. Fusion complete."
Stepping over rubble, Senya strode out in high spirits.
"I have reached the peak of super Kage."
Feeling the surge of ocular might, he grinned.
He moved at once to test the change.
Susanoo. Amaterasu. Summon Flash.
After a round of trials, he found he could run each fearsome art with ease, and not a hint of drag tugged at his eyes.
"Now I am only a Nine-Tails short of the Madara at the Valley of the End."
"My Sage Body is nearly complete too. If I truly crossed blades with that version of him, who knows who would win."
He still hoped to awaken Wood Release.
Yet with the Sage Body near perfection, there was not a whisper of it.
"That makes no sense. Yamato has no Sage Body and still uses Wood Release."
"If the Sage Body at full cannot awaken it, I will have to consider grafting Hashirama's cells."
A last resort.
For now he preferred a natural awakening.
Once he finished familiarizing himself with the new eyes, he did not linger in the forest.
Today was a clan assembly.
In the past, he sent a shadow clone.
With his power, no one had ever seen through it.
This time was different.
War pressed close, and Fugaku would take up the clan head's mantle and lead the Uchiha to the front.
Not that this was the true reason for his return.
The real draw was this: Itachi had been born.
With a direct heir, the Great Elder had used the good news to seat Fugaku as clan chief.
"Let me see whether the infant god of the clan already has those laugh lines."
Back when he watched the story, Senya had grumbled at Itachi's design.
How did a face that handsome carry lines that deep.
It had yanked him out of the moment every time.
With a crooked smile, he flashed away.
...