EDIT 4/2/2015: Oh my gosh! My anonymous reviewer Magykal-guest PLEASE find me on AO3 so I can talk to you and thank yu for all the awesome reviews. Please please please! Dang you're fast!

A/N: I'm sorry this is so short, but it's short because I finished writing the first chapter of the Ancient Egypt Seth-centric prequel. I've posted it under the title Shadow Beginnings and added it as the next in the series this fic is in Shadow Justice. Just click the Shadow Justice series in the info box above and it'll take you to the series page where all the fics in this series are posted together in chronological order: My Aibou, Shadow Justice, and now Shadow Beginnings.

Chapter summary: In which Ba and Ka disagree.

Of Ba and Ka

Kaiba woke in his soul room curled around the stuffed sha and with the sheet and blankets on the futon tucked around him forming a cocoon. He could feel his body in the real world still sleeping soundly, so he wondered what could have woken his soul in here.

He heard the sound of glass brush stone and sat up, turning around to look at the other person in his room. Seth was kneeling on the floor piecing the mosaic of Kisara and her Blue Eyes White Dragon back with tender care. Seth was so focused on his task, he had neglected to notice Kaiba wake.

"You don't have to do that, you know," Kaiba said, smirking when Seth literally jumped in shock.

Blue eyes identical to his own whipped to him, a blush coloring tan cheeks. Seth swallowed and looked away, eyes returning to the almost completed mosaic once more. Tan fingers stretched out and caressed the glass and stone face of Kisara.

"I thought I could take it," he breathed, voice almost too quiet to hear. "Seeing her, I mean."

Kaiba said nothing, waiting for Seth to continue, knowing he had more to say.

Seth heaved a sigh that sounded suspiciously like controlled sob. "But then I summoned her and I..." His eyes closed and Kaiba felt more than saw the tears trickle down Seth's dark face. "It hurt. Seeing her like that, it hurt. I wanted to embrace her, to hold her, to hear her voice again." The sobs were no longer controlled. "But I never will and it's all my fault."

Kaiba kicked off his covers and stood, walking over to Seth's shaking form huddled on the ground. "Oi," he said. "Crying doesn't help anyone. All it does is take up time and effort that could be used to fight back."

Seth coughed a laugh. "I know," he said in a broken voice. "Believe me, I know." With a visible effort, Seth wrapped his arms around himself and took in a deep breath. He held it for several seconds, releasing it only when he felt somewhat in control of himself. "I apologize for my unseemly behavior."

Kaiba clicked his tongue. "Too formal."

Seth breath a laugh. "So you have said."

"And I'll keep saying it until you stop acting like an idiot." Kaiba watched Seth bow his head at his words, catching the small smile on his lips. "It wasn't your fault," Kaiba said. "You didn't do anything. We didn't do anything. He did." Kaiba's eyes darkened. "And we'll make him pay."

"How?" Seth asked. "We can barely stand hearing his name without trembling in fear."

"You tremble with fear," Kaiba corrected. "I tremble with fury."

"You think me weak," Seth said, the edge of annoyance tinging his words.

"I think you're too emotional," Kaiba corrected.

"In Ancient Egypt, it was commonplace to express one's emotions openly," Seth countered. "You should remember that."

"I do. I just acknowledge I'm not in Ancient Egypt anymore but Japan, and now the United States of America," Kaiba said. "It's not wrong to express emotion, but it should be kept under control when not in private."

"That is unhealthy."

Kaiba shrugged. "It's expected. In public, emotions are dangerous. In private, they are acceptable between yourself and someone you trust absolutely."

Seth hummed and stood, turning to face Kaiba. Neither spoke for several long minutes, they just stared. Then Seth breathed a short laugh. "We certainly are something, are we not?" he said, tilting his head so one long braid fell over his shoulder. "We even hold barriers between ourselves."

"I was you," Kaiba said. "I do not know you."

"And yet you allow me unrestricted access to your deepest, most sacred self," Seth countered.

"You would've gotten in here on your own one way or another."

Seth shook his head. "Not if you commanded me not to. This is your soul room, not mine."

Kaiba snorted and crossed his arms. "I've seen your soul room," he said. "It's barren except for the corners."

Seth dropped his eyes. "I did not have much reason to live at the time of my death," he said.

"Pathetic," Kaiba muttered.

"Yes," Seth said raising his eyes to stare directly at Kaiba in challenge. "Pathetic indeed."

Kaiba snarled but could not deny it. Seth had been him and he had been Seth. They were both guilty of being pathetic. It was galling to admit, but here in Kaiba's soul room, neither Kaiba nor Seth could lie to one another. Oftentimes, the truth cut deeper than any fancy words and preferable lies either could spit out.

"And yet you still accepted me," Seth murmured, drawing Kaiba attention back to him. "You stopped smothering me and have begun to accept me as a part of you. You never did that before." Seth stepped closer to Kaiba. "I used to have to fight you for every centimeter of space you held. It was a fight I began to doubt I would ever win."

A dark hand rested palm down on Kaiba's folded arms, pressing gently while old blue eyes continued to stare deeply into an identical, younger pair. "And then one day, out of the blue, you let me in. You stopped fighting me and let me in. You did not trust me completely, you still do not." Old eyes saddened. "It hurts me deeply knowing that, but I accept what you have given me and I will continue to do what I can to aid you."

Kaiba sighed through his nose, reaching out and flicking Seth's forehead. Seth squawked in both pain and shock. "That's for being a formal idiot again," Kaiba said. "I'm not a woman for you to woo. I'm Kaiba Seto, myself. I was you, but now I'm me. That won't be changing any time soon."

"And I do not want it to," Seth said, still rubbing his forehead and glowering at his reincarnation. "I just want you to trust me."

"I'll decide if and when that will happen," Kaiba said. "In the meantime, stop pushing me."

"Why?"

Kaiba froze, not expecting the question. "Why what?"

"Why do you want me to stop pushing you?" Seth asked. "Is it because you think you might waver and give in if I do?"

"No."

"Then is it because you fear me?"

"I fear nothing!"

"Do you hate me?"

"No."

"Then why?"

Kaiba said nothing, clenching his fists and glaring hard at Seth who met him with an equally dark glare. "Because I am whole," Kaiba snarled.

"You and I both know that isn't true," Seth replied "Maybe you were once, although I doubt it. But now you know you're not." Seth stepped closer. "You cannot live without me," another step, "and I cannot exist without you." Another step. "We are two halves of a whole." Seth leaned up to whisper in Kaiba's ear. "My Ka."

"I am not your Ka," Kaiba growled, grabbing Seth's shoulders and pushing him back against the Egyptian wall. "You are a Ba whose Ka was ripped from you and turned into a beast under your command, leaving you to wander alone after death. I am not a beast but a thinking human being under my own command. I can live alone, you cannot. I am whole, you are not."

Seth grimaced at the force of Kaiba's grip, wincing as blunt nails dug into his bare arms. "You cannot deny it. Look at you. Your soul is not whole; it probably never was. You need me."

"I don't."

"Then banish me."

Kaiba stilled. "What?"

"Banish me," Seth repeated, relaxing in Kaiba's vice-like grip. "If you truly think you can live without me, than banish me."

Kaiba's eyes hardened and he gathered his Shadows. But no matter how riled he got, he could not force himself to banish Seth. It felt like destroying a part of himself and his well-developed survival instinct prevented him from doing that. He growled at Seth who just looked at him.

"You can't, can you?" Seth whispered. His old eyes closed and he leaned limply against the stone and wood wall. "Why do you deny what your soul already knows?"

"I won't loose myself," Kaiba said.

"And I do not want you to," Seth insisted, opening his and pinning Kaiba with them. "I do not want you to stop being Kaiba."

"Then leave me."

Seth shook his head. "I cannot do that." He smiled helplessly. "I can no more leave you than Yami can leave Yuugi."

Kaiba shook, visibly fighting with himself. He abruptly released Seth and turned away, returning to his futon in the Japanese side of his room and climbed under the covers. "Good riddance."

Seth waited until he was sure Kaiba's soul was fully asleep before allowing himself to slump, sliding down the stone and wood wall to sit heavily on the ground. His arms wrapped around himself as if to hold himself together. The sunlight from the modern wall dimmed, hidden by a layer of clouds. The same happened to the moonlight spilling through the open Japanese circular window. Slowly, softly at first, then building to a steady drizzle, rain began to fall accompanied by the occasional distant rumble of thunder.

Seth laughed softly. He could influence Kaiba's soul room to this extent and still Kaiba refused to believe him and accept him. Seth had no desire to become one soul with Kaiba, but he did want to have a symbiotic existence that went beyond what he had. The Pharaoh and Yuugi were both a Ka and Ba who acknowledged each other and remained with each other as separate individuals. Was that such a bad thing?

Kaiba was strong, surviving a long time as a lone Ka. But now with Seth as his Ba, he was struggling. Seth felt Kaiba's desire to maintain his individuality and endorsed that wholeheartedly. But Seth also desired to be acknowledged and accepted. Until he was, he would continue to grow weaker until he would eventually vanish.

He had already experienced death once. But even though he had embraced it then, he desperately wanted to live now. He had a reason to live. His first and best friend, his cousin had been reborn as Yuugi and Yami. He had Mokuba through Kaiba. He had Shaadi and Ishizu and Mai through both Kaiba and his own memories. He had a purpose now. He wanted to live.

But he was a Ba and a Ba cannot survive long without the presence and acceptance of it corresponding Ka. That meant if Kaiba refused to accept him, Seth would simply grow weaker until he faded away, vanishing into the Shadows as if he had never existed.

He just wanted to live. Was that so wrong?

"Aibou!"

Yami held his precious other half tightly, calling out to him with all his strength. His voice echoed in Yuugi's soul room but he could barely get a response from the young, weakened King. When he felt the balance begin to return, he felt Yuugi begin to stir. He called to him by name and by his pet name, hoping to get an answer to one or the other. Then, to his immense joy...

"Mou hitori no boku."

There were few times, Yami could think of that brought him to tears. This moment was one of them. He embraced his aibou, holding Yuugi close and weeping in joy and relief. He had felt the familiar all-devouring panic and despair he had hoped to leave behind with his memories of DOMA begin to creep back into his mind, squeezing his heart.

Yuugi blinked in exhaustion but smiled and held Yami close. He whispered soft words of affection into his other self's ear, kissing the reddened flesh gently. One of his hands moved soothingly up and down Yami's back while the other scratched Yami's hair tenderly. He moaned when he felt Yami begin to kiss him, shivering at the feel of soft lips pressing against his skin.

"Mou hitori no...boku," he breathed, tilting his head back and allowing his eyes to drift closed.

"No!"

Yuugi's eyes flew open at Yami's terrified cry. The crimson eyes he adored stared into his pleadingly.

"Don't close your eyes," Yami commanded. "I need to know you're alive, here, and not..."

Yuugi's smiled softly, nuzzling Yami cheek. "I understand." He kissed Yami's ear and whispered, "I'm here. I'm right here. I'm not going anywhere." Yami started shaking. "I promise," Yuugi said. "I won't leave you ever again. Never."

Yuugi held Yami and continued to just talk to him, reassuring him until he felt his other half drift off to sleep. When Yami was finally out cold, Yuugi allowed his own eyes to close and sighed.

He could feel Kaiba nearby and Seth if he reached deep enough. He had his suspicions of Seth's true existence, but kept his opinions to himself. Kaiba would figure it out eventually. Hopefully before Seth vanished. Kaiba needed the conscience and stability Seth offered. Not to mention, two half souls existing separately but working together were better than a single, lone half, in Yuugi's opinion.

Oh well, Yuugi needed to sleep and heal his overloaded soul. Hopefully things would have calmed down somewhat by the time they woke up. Come what may.