Self Surrender

The confused Mozu turns back around only to see the boy whom he had just decapitated rise back from the dead. Before he can strike again, the entity teleports behind Mozu and whispers.

"Hold still."

The entity walks towards his near-dead friends and uses the reverse cursed technique to heal their legs, and other injuries as they lay unconscious. The being looked like Akumu but he was definitely different. His face and body were identical but this one's hair had turned completely white, and his eyes burned an even greater color of amber. 

He looked back at Mozu and declared his identity.

"I am the shadow of Saigo Akumu, the true self. I am the embodiment of his despair, denial, and self regret."

[Mozu] What does that even mean?

Akumu teleports in front of Mozu, grabbing him by the head and throwing him into the nearby cliff face. Mozu tries to retaliate by throwing another dismantle attack which Akumu confidently tanks. Somehow the attack only damaged his uniform.

Akumu once again teleports in front of the straggling Mozu and kicks him through the mountain into the forest on the other side. He then follows it up by chasing Mozu through the hole that he created and jabs him in the gut sending him high into the sky.

Mozu quickly heals from the attacks but is again relentlessly barraged by waves of kicks and punches breaking Mozus' bones before being grabbed by the head and smashed into the ground. Akumu stood over Mozu and said to him mockingly,

"Didn't you say I was boring you before? This isn't even enough to be considered a warm-up for me."

Frustratingly the man slammed two of his hands on the ground instantly spawning Intense flames that burn the area to cinders and ash. As he slowly got back up a powerful kick sent him flying through the sky.

[Akumu] I wouldn't even be able to cook a meal with these flames.

Mozu once again sends a barrage of dismantle attacks toward Akumu however he instantly dodges them all, grabbing Mozu by the foot and slamming him into the ground once more. 

Surprisingly Mozu had cut off his own foot, then copying Hagones' binding vow transformed it into a powerful explosive then used it as an opportunity to run away. The explosion however didn't even knock Akumu on his feet and he only continued to watch the struggling Mozu.

Now having enough of the situation, Mozu two powerful arrows of flame by drawing on from his hands like a crossbow. He shouts at Akumu before shouting,

"BURN TO ASH"

The two arrows hit their target perfectly causing a great explosion that could be seen even from the sky. The explosive cursed energy eviscerates everything in the surrounding area.

As the dust fell an eerie presence slowly emerged from the fog. The attack only slightly destroyed Akumus' clothes but other than that he was completely unharmed. 

[Akumu] My turn again?

Akumu quickly jumps up over the fearful Mozu, spawning multiple black whips over his head that were each the size of a building, instantly crushing him like a human stepping on an ant. Mozu uses his cleave to slice away a small area of the black whips allowing him to escape. But Akumu quickly meets him on the other end.

[Akumu] My other self could never hope, to master this power without accepting me. He doesn't even realize the true potential this body holds.

He summoned a large black whip in the shape of a greatsword slicing Mozu in half. Akumu called out the technique,

"Black Slicer."

The split apart Mozu summons another pillar of pure red flame that slightly pushed Akumu away from him. He quickly healed his missing lower half as he clasped both his Arms together and shouted,

"DOMAIN EXPANSION: FOUR-FOLD ESSENCE FACTORY"

Once again the shrine of death and chaos spawns behind the man this time all being focused on the one enemy standing before him. He Summons an almost endless barrage of Cleave attacks that swarm Akumu seemingly killing him.

[Mozu] DIE YOU, INHUMAN BASTARD, THERE IS ONLY ONE GOD IN THIS WORLD AND THAT'S ME.

Akumu slowly walked up towards the man, the only thing getting damaged was his now shredded shirt. His body on the other hand he was almost unharmed with only a few scratches instantly healing faster than they could form. Shaking his legs Mozu shrunk back in fear before asking,

"What are you?"

Akumu only responds, "I already told you, I am a shadow, the true self."

Akumu then forming a hand sign utters overpowering words.

"Domain Expansion: Pure White Palace."

In an instant, the world had vanished transporting the two to an empty space. There was nothing in the world they were in. The world was white and empty and hollow. Mozu asks,

"Where are we?".

So Akumu begins to explain

"This world isn't an ordinary Domain Expansion. But it is me drawing out my own subconsciousness to reality. As a result, my Domain cannot be broken unless you can perform the same action."

[Mozu] Is that even considered a domain expansion?

Akumu simply smirks at himself, not even being aware of what is and isn't anymore.

Before Mozu had time to beg for his life though, his head is instantly blown off by an incisable attack. The metal collar around his neck is destroyed followed by multiple holes forming in his heart chest. 

What was once a pure white innocent world had been dyed in blood and malice.

As the domain slowly came undone what was once a beautiful forest with a decently sized mountain had forever been scared by that battle between the false deity and shadow.

Akumu now walking away from the remains of the body felt a sense of accomplishment from defeating the enemy. Before he could go reunite with his friends however he senses a mysterious presence emerge from behind him.

As he looked back, a dark red gas flew out the dead corpse. It formed into a single head that possessed two sets of eyes. It was the sealed soul of Ryomen Sukuna, he then spoke.

"You completely overwhelmed that power-stealing bastard. When I figure out how to get my main body out of that place you will be the first person I kill."

Before Akumu could respond the phantom disappates into the sky never to be seen again.

Akumu too felt his own consciousness fading. The shadow who had possessed his body felt the binding vow taking effect. Angrily he wishes that he bargained with his real self for a little more time, but alas his turn was over.

He collapses to the ground as he falls asleep peacefully.