{Flashback}
*Arceus POV*
I watched with tears in my eyes, as the humans I had created and cherished for so long began to war with each other. I wiped the tears from my eyes, and turned to the figure who had just landed nearby, transforming into his human form.
"Y/n," I growled, "Did you do this? You and your...Chaos?!"
He did not respond, walking over to look down on the humans. He scanned the fighting humans with an almost proud gaze, one that seemed to indicate he had gotten the results he wanted.
"Answer me, Y/n," I growled, "DID YOU DO THIS?!"
He took a deep breath, and turned to me. His hands were clasped behind his back and his eyes shone with bright red determination.
"You allowed yourself to create these creatures, and to give them them qualities we once held for ourselves," He said, a betrayed tone in his voice, "Without consulting me, you gave our greatest qualities to these fools. You even gave them gods and deities to control certain realms and elements of the world. What happened to the days it was just you and me? We could rule the world together, our power unmatched, yet you bow for these... humans?"
He spoke with a disgust that scared me. He was truly angry over these humans, but why.
"Y/n, what has changed?" I asked, "We're both still here, are we not? We're still a family, we've just grown."
I attempted to put an arm around his shoulders and hug him, but he pushed me back.
"No, you've betrayed me, and that's it."
He turned and began to walk away, stopping as his wings shot out of his back.
"Wish you luck with your... humans."
With that, he flew off into the air, disappearing in a flash.
[Timeskip]
I sat in my throne, which sat at the head of my court of gods. I was listening to Heatran and Groudon go at it with Kyogre and Lugia once again about the seas or some garbage.
I found myself scanning the crowd of gods and deities that sat around me. To my sides, my children sat there. They were usually the first I talk to before making a decision.
As I scanned the crowd, my eyes wandered to Cresselia, the ever-cheerful, yet estranged daughter of Giratina. She was planted front and center, prepared to calm everyone if time came.
Nearest to the door, hidden in shadows, was Darkrai. He never spoke during meetings, most likely angry about his father's imprisonment. I couldn't blame him, nor could I expect him to understand, being much younger that my war with Y/n.
Suddenly, the legendaries that were in the center went silent. The room seemed to drop a few degrees, and the sky went dark. A soft glow of red covered everything, as a portal opened up above.
A massive shadow came out of the portal, taking the form of Y/n in his Origin form. I understood that this was merely a shadow of his power, much weaker than my brother's whole power.
It grabbed onto legendaries and began to throw them around the room, slamming them into walls and floors. He destroyed the court, knocking out most of the legendaries except for his children, my children, and me.
"Don't worry Mom!" Palkia called, "We've got him!"
They jumped up and charged at him, attempting to attack in unison. They were easily whacked away by a slimy tendril, sent flying into the wall. Cresselia began firing arrows at the shadow, forcing it backwards, as it refused to attack her.
"Cresselia, leave," I ordered, "I shall handle this."
"Are you sure?"
"Absolutely."
She flew off and disappeared into the sky, as the shadow turned to me with a growl.
"Come shadow, let me send a message to your master."
I brought out my spear and flew at him, stabbing towards his massive chest. I easily shot straight through, destroying him in a matter of seconds.
The shadow let out a terrible growl, and disappeared into his portal once again. As he did, the light returned to the room, revealing Darkrai as the only one left standing. As the legendaries began to stand up, healing themselves from the attack, they began to point fingers.
"Darkrai..." I trailed off.
"He's a traitor!" Heatran yelled, "He belong with Giratina in the Distortion World!"
"He is begot in darkness, there he should stay!"
"If that's how you see it, so be." Darkrai replied with a shrug.
He disappeared out the front door, turning to me once more.
"Don't ignore the warnings, Arceus," He warned, "He will return."
Those words struck a fear in my soul, deeper than ever before.
Not at the fear of Y/n's return, but at the fear that I would have to face what I did to him, once and for all.