A/N: Seriously though, who else thinks Sasuke looks like Izuna?
Madara blinked at the boy before him, his muddled vision slowly clearing itself, that face was hauntingly familiar. Yes, that face...
No, he shook his head in confusion, it couldn't be him...
"Izuna?" His voice trembled in delight. "Is that you Izuna? Oh Izuna, I've really missed you!"
Neglecting a bemused Shinobi Alliance, the vexed seven tailed beasts and pretty much everything around him, Madara pounced onto the young kid and suffocated him with a bone-crushing hug.
"Heh?" The blond, blue-eyed boy with whiskers that is supposedly the nine-tails jinchuriki stared dumbfoundedly at the two. "Sasuke-teme, why are you two hugging?" His mouth hung open in confusion and sensing how awkward this situation has become, Naruto began rubbing restlessly at his head to ease the disturbing scenario in front of him.
"I... don't... know..." Sasuke, who the boy actually is, coughed and tried to wrestle free to little avail. Whenever he resisted, Madara would hug harder and whenever he tried to convey the fact that they've never actually met before the battlefield, Madara dismissed this absurd presumption.
"Oh Izuna, why did you never tell me you were alive the whole time? Why Izuna, I've suffered so much because of you!" Tears were streaming down Madara's single Rinnegan eye as well as the other empty eye socket. "Heck, I even tried to initiate plan Tsuki No Me, if I had known that you were alive..."
The man's voice was drown in a series of sobbing fits while Sasuke stood there rigidly, unsure what to do.
The rest of the Alliance stared at them and an awkward silence dawned amongst the battlefield.
"I... am... actually... not ... Izuna..." Sasuke struggled to muster his voice.
"Don't lie to me, I could recognize your looks anywhere!"
"...really... he's dead and if he's still alive he would have been an old hag." Sasuke finished his sentence flatly.
"Aha!" Naruto, having one of the slowest reaction rates when it came to non-fighting matters, finally understood what's going on. "So, you, porcupine head," he pointed at Madara, "seems to have some misconceptions. That guy you're hugging is my best-friend Sasuke! Yeah, you heard it right Sasuke: despite how you almost-nearly killed me, ran off to Oto with a snake-obssessed pedophile, attempted to kill me AGAIN, refused to return to Konoha, tried to kill Sakura and Kakashi-sensei at the Summit, I'm still your best-friend!" He concluded his monologue triumphantly.
"No... I don't believe it!" The older Uchiha was still as stubborn as ever, clinging onto the notion that the poor kid in front of him is is little brother.
"Yeah, what the dobe said."
"I know! He's little 'zuna's reincarnation!" Madara declared cheerfully.
"Reincarnation doesn't exist," Sasuke rebutted the man.
"Why not? There's Edo Tensei and Rinne Tensei to bring back the dead, obviously reincarnation must exist!"
"Except that reincarnated people cannot be Edo Tensei'd..."
"And my younger brother wasn't! So you're essentially Izuna!"
"You are, you two practically look identical!"
This time Naruto who was still gazing at the two spoke up: "you know, all Uchiha's ARE identical-"
"No we do all NOT look identical!" Both Madara and Sasuke protested indignantly.
"All right, all right! But seriously, couldn't it just be a mere coincidence that Sasuke and Izuna look alike?"
"No!" Madara answered him declaratively, quenching every hope of anyone reasoning with him thereafter.
In the meantime the remaining Shinobi Alliance were starting to make themselves comfortable and even the 7 tailed-beasts joined the whole crowd of spectators.
"Popcorn?" Fodder Shinobi 203 asked Fodder Shinobi 555.
"Thanks," he grabbed a handful of it.
"Love real-life movies, especially those involving dramatic family reunions," the other nodded joyously.
Therefore what was ostensibly the conclusive final battle of the Fourth Shinobi World War transpired to be a "reunion" between two "lost" family members.