Spirit of Reversal against the World

I've been thinking about how to use time travel to my advantage for the last 4 days, and I think I've finally come up with the perfect plan.

To use time travel to my advantage, there are a few steps that need to be taken. First, I need to bring Origami, Shiori, and Mukuro with me, and I have specific reasons for bringing each one to suppress any complicated variables.

Shiori needs to come so she doesn't forget everything I've said and done for her. That way, I can ensure she has memories of both worlds. I plan to take her after knocking her unconscious, so she won't know she's traveled to the past.

Mukuro needs to come to prevent the memories from the illusion from being forgotten, as I'm not sure if my new timeline self will use that on Mukuro, and it would be bad if she didn't remember it.

Origami needs to come because she's the key, so I can maintain the original timeline to a certain extent.

I've noticed some patterns. First, the past Origami always has some contact with spirits. Second, the past Origami always loses her parents in one way or another. Third, the past Origami is always "saved" by someone, in this case, Shido. Fourth, Origami always has a target for her hatred, and that target always has spirit power. However, the important thing is that these things don't necessarily need to be done by Shido they just need to occur for the timeline to be maintained.

In other words, I can do all of these things myself. I can kill Origami's parents to have her hatred, I can reveal the spirits, I can use my illusions on the child Origami and "save" her. This way, I can also obtain two Sephiras one from the current Origami when I kill her, and another from the Origami of the new timeline.

And the best part is that by marking Origami with Belial, my past self will know that the world has changed because of me, since the Belial mark doesn't disappear. So, as soon as my new timeline self awakens Belial, he'll realize I'm the one responsible for going back in time.

This way, I can have my past self help me as if it's a message. Of course, my plan has more phases for certain corrections, and I'll put it into practice soon.

Besides, this way, I can make the world more or less the same, with only a few real changes.

"Mukuro, come here," I call from the living room.

"Yes, brother, do you need something?" she says enthusiastically.

"Can you knock out the Origami downstairs and bring her here?"

Mukuro agrees and happily goes downstairs.

"Kurumi, I want you to kidnap the unconscious Shiori. We're going to travel in time now, take all the [Time] you need to bring the four of us."

The shadows tremble, and after 2 minutes, Kurumi appears with the unconscious Shiori. Mukuro also comes upstairs, bringing Origami.

"Hihihi, from what I've seen in your notes, you've found an interesting way to manipulate everything to your advantage," Kurumi says with a chuckle.

"Of course, let's get going," I say to her. She then activates the Devouring Time Castle, and after 30 minutes, she's ready.

"Alright, Aurelio-san, I'm ready," she summons her Angel.

"Whenever you're ready," I say, and she shoots us four.

Suddenly, everything changes. I'm in the city, and there's a fire burning.

"KURUMI, I KNOW YOU CAN HEAR ME! SEND SHIORI AND MUKURO BACK!" All I want from those two is for them to remember the old world in the new timeline. The conditions for this are having gone back in time and having spirit power in their bodies. Naturally, they don't need to stay here, as they've fulfilled their role.

Soon, the two return, and I'm left with the unconscious Origami.

"...I'll ignore that for now, I need to be quick." I activate my Astral Armor and quickly go after the past Origami.

"There...I need to mark her."

"Belial," I summon Belial for this mission. I accelerate and soon I'm close to the past Origami. I lightly hit her and then back off.

Origami soon falls to the ground and begins to "hallucinate." I've defined everything in the illusion I'll be the one who killed her parents, but she'll be unable to see my form, appearance, or voice. She'll only know that [Shinigami] was the one who killed her parents.

I see Origami's parents trying to wake her up.

"Perfect."

I have a plan to invert Origami now and steal her Sephira. I accelerate towards Origami's parents and knock them out. Then, I take Origami from the ground and take her away.

"Hey, girl, are you okay?" I take Origami out of the illusion. In the illusion, she saw me saving her from being killed by the spirit, fulfilling most of my goals.

"Hick Hick Buaaa" She hugs me and cries.

"It's alright, girl," I comfort her.

'I have to be quick. Even with the reversal, I don't know how long I can stay in the past.'

"Do you want revenge, girl? The one who killed your parents is a [Spirit], a horrible calamity that has appeared in this world, and the one who killed your parents is the Shinigami. If you want to get revenge, I'll help you. I'll give you this."

I hand her a paper that will lead her to a place where she can find the AST.

"In that place, you'll gain the strength to get your revenge...I have to go now, so take care."

She's still crying, but it doesn't matter. I've placed a mini-illusion so that throughout her life, she'll "see" me occasionally. I plan to form a friendship with her using the illusions, and I want to see what Origami will tell me in the new timeline.

After all, in the new timeline, from her perspective, we'll be friends.

I run out and when I'm in the alley, I start flying again. I grab Origami's parents and take them to where the unconscious Origami is. I wake them up but prevent Origami's parents from speaking while keeping them restrained.

"...Who are you?" Origami asks in her usual mechanical way due to the illusion, not knowing who they are.

"Nobody relevant. So, let's make a deal, Origami. I'll take you to the past, and I won't personally kill your parents, and in return, you kill those two here."

She ponders it.

"Think carefully, Origami. Your parents or these two irrelevant strangers? But answer quickly, I'll give you 1 minute. If you refuse, I'll kill your parents."

Her mind seems to be racing at 1,000 miles per hour.

"I-I'll do it, okay..."

"Of course, here you go. Let's get this done more or less quickly, okay?"

I want to see how far Origami will go, and if when she inverts, the high amounts of negative emotions will influence how much power she'll have.

According to my calculations, by the time this is over and I return to the new timeline, it'll be about halfway through the preparations for the festival. Although in the anime, everything seemed to be done in 1 day, in reality, it took much longer around 1 month of preparation.

While Origami thinks about how to do it, I start using my ability. I'm going to kill this current Origami and steal her Sephira to take with me. That way, in the new timeline, there will be two Metatrons in the world, and later, I can obtain the second one from the new Origami.

I wonder how the two Metatrons will work in the world.

"Here, to help." I toss a blade to her.

"...What exactly do you want me to do?"

"How about dismembering them and then cutting off their heads? But don't damage the faces."

When I remove the illusion, Origami should know exactly who she's killing now.

She soon starts walking towards them, who are immobilized. It's funny to see Origami, who calls the spirits "monsters" for killing, now doing the same thing out of selfish desire.

"Sorry," is all she says. She then begins her work, her parents screaming in pain and desperation as she cuts them with skill.

'As expected of a former AST member.'

They don't know she's their future daughter, so it's not like there's a sense of betrayal.

'Tsk, my energy has started to drop...' Now, my energy is being spent, which means that from now on, I'm no longer being maintained by Kurumi's power, but by my own reversal and a Reiryoku barrier.

"I think that's enough, Origami, you can kill them now." I had planned for her to torture them... but time is time, and mine is limited, as I still need to fight and kill the inverted Origami.

"Okay..." She cuts off their heads with the blade, her skill with cutting weapons clearly on display.

"Inefficient, don't you think?" I say to her, seeing how much force she needs to use for this task.

I deactivate my abilities that were restricting her energy, and from now on, she can Invert and use her powers.

"Origami, do you know who these people are?" I ask, and she looks at me with that emotionless gaze. She was a bit colder than I expected.

"No."

"Then hold the heads of the two and look closely." She does as I say.

I soon deactivate the illusion, and her eyes widen in shock. In an instant, her Reiryoku grows to tremendous levels.

"COME ON, ORIGAMI, SHOW ME THAT I DIDN'T MISJUDGE!" I fly, breaking through the building and distancing myself, as a dark energy emanates from the building. In this fight, the winner will be the one who kills the other first.