The Marriage of the Eon

Prologue
The siblings were deep in thought when they saw some of their shinobi stumbling through the gate. Most were bleeding heavily and some were carrying their comrades. Ryo immediately bolted to them and asked what had happened. They said that there was someone in the mountains who extracts souls. Ryo then looked at the shinobi being carried and he knew they weren't lying. Ryo told his siblings about the situation and they set out to where he was last seen.

Kouwa awaited within his mountain cavern, sensing the chakra of an eye he had been searching for. Three pairs of eyes? he thought to himself, sensing the trio getting closer to his location. Might as well make the journey easier. he thought, as he suddenly flickered behind them. "I believe you've been searching for me."

The triplets leapt back thirty feet and activated Senrigan Sage Mode. Teizen whispered, "Ni-san, his chakra is overwhelming! He's like a god." Shiena piped in, "I also am worried about fighting him." Ryo ignored his siblings' worries and calmly said, "Yes, we were. Now, who are you and why are you extracting random people's souls?"

"I extracted the soul of corrupt shinobi. Those who will plague this world. I will not allow for these corrupt individuals to plague my 's creation. My name is Kouwa Ōtsutsuki, and I am the Sage of Dual Paths." Kouwa answered. "Now, who are you three?"

"O-otsutsuki?!" Ryo stammered. "But... What... Where?" Teizen then calmly placed his hand on his brother's mouth and said, "I'm Teizen Uchiha, he is my older brother, Ryo Hyuga and our sister, Shiena Uchiha.

"The eldest...a vessel for my nephews..." Kouwa stated. "I understand you all have the Senrigan. I sense reasonable amounts of chakra dwelling within all of you...Come...fight me."

Ryo calmed himself down and asked, "This is a friendly brawl, right?"

Kouwa stared at the three. "It shall be friendly, as I doubt you three could force me to stop toying with you."

"Yes, sir!" the three of them said. All three simultaneously used Chibaku Tensei and Blaze Release: Kagutsuchi.

"You call this an attack?" Kouwa teased. He raised his hand, and a hand made of cosmic energy shot out from his palm, absorbing the attacks. The hand then shot forward, and ended up only centimeters away from the trios face. "Release." Kouwa said, and the hand shot out the techniques at point-blank range.

Their reactions were at light speed. Teizen and Shiena teleported away while Ryo teleported behind Kouwa, activated Senrigan Burst Mode and used Six Paths: Ame-no-mihashira, trapping the four inside its dimension.

"Interesting. This realm...I sense some sort of poison? It shall not impact me." Kouwa said, staring at the trio. "You three are...interesting shinobi. You may think you're at an advantage, but you are wrong. Ryo, you have always though of youself as an invincible child, due to you being the 'Second Sage of Six Paths'. You may be the vessel for my nephew's chakra...but I have Hagaromo's chakra. You are at the disadvantage here. Even in your own realm."

Kouwa raised his hand, and the dimension began to shake. Stormclouds appeared in the air, mountains began to rise, the wind current picked up, rivers were formed, and even tress grew. Soon, the dimension Ryo had brought them two had transformed into a luscious world, with the potential to support actual life. "This is what I can do. A mere fraction of my power." Kouwa began, bringing his hand back to his side.

Kouwa stepped forward, and spheres of black shot out from his back, soaring into the air. As they flew up, moutains flew towards them, the rivers waters flew up to the multiple gravity spheres, until they were no longer in sight. "And then they came." Kouwa muttered. Immediately, large spheres of natural power came crashing down, right towards the targets.

Ryo teleported his siblings out of the dimension and took the brunt of the attack. Once the dust cleared, Ryo was on his knees, barely breathing and bleeding profusely everywhere, using a cane to stay upright. "If you wanna kill them," he groaned, "You have to go through me first! I will protect my siblings even if it means!"

"Do you actually think that I am trying to kill you?" Kouwa asked, shaking his head. "All my attacks have been much weaker versions than the true extent. I am not trying to kill you."

Kouwa raised his palm upwards, and snapped his fingers. The dimension they were in shattered, and soon the duo was back in the real world. "Do you surrender? Or do you wish to continue?"

Ryo put both arms in the air and stepped in front of his siblings. "I surrender," he said, "Just please don't hurt my siblings."