Horcrux - 1

Yes, there wasn't a horcrux of Voldemort in the orphanage that Tom Riddle grew up in in the original canon of Harry Potter, but, I knew that some god would always give me a chance for a big power boost at the beginning of each transformation in return for the high possibility of my death.

For example, when I had first "transmigrated" (dreamed myself) into the Demon Slayer world, I had been given the chance to throw myself at Muzen in the beginning, and so I did, becoming the demon that I had become.

Obviously, at the time, I could have definitely been eaten by Muzan, but it had all worked out in the end.

As for now, letting a horcrux of Voldemort possess my body was basically the same amount of danger, if not more, as this dealt with souls and dealing with souls was always a tricky matter, but I would just have to overwhelm Voldemort's soul.

It wouldn't be that hard I thought, I mean, I had lived for about 500 years more than him by now, thus, my soul was obviously a lot stronger.

That was why I had happily taken this risk, there was too great of a reward to give up.

So, I went and acted fool as I felt the Horcrux creeping into my body.

'Hmm… it's pretty slow, does it actually think that this is a trap?'

'Welp, it's too bad now!'

Seeing that the entirety of the horcrux had entered my body, I immediately seized the opportunity and grabbed at the Horcrux, pulling it in deeper.

If there was a comparison that I could use for what was happening, as going into the details of a soul fight was a little hard to explain, and my vocabulary wasn't there technically, I would say that the horcrux had been an unfortunate fly that had fallen into a pitfall plant trap, ie. me, and was now helplessly struggling against my sticky grasp in a futile attempt to escape.

In the end, nothing it tried to do could work and so I was able to merge our two souls together.

And with this came the reward I wanted, the memories of all the spells he had used before, and how to use them.

Obviously, now, I could become a total genius in the magical circle, but, of course, I wanted to keep as low key as possible.

Also, I wouldn't be able to practice magic do to the intervention of the Aurors, so I wouldn't able to see myself in action until I got to Hogwarts.

Unless…

What do you know? I could definitely make this work, I was an overpowered bastard after all.

'Domain Expansion: Boundless Abyss'

With that, time immediately stopped around me, as a absolute black enveloped just my body.

Yes, I had gone to the JJK universe in one of my previous dreams, reincarnating as Gojo's younger brother actually.

And yes, my domain expansion was the complete opposite of Gojo's "Infinite Void".

If his made the opponent feel everything, mine made the opponent feel absolutely nothing, as if they were dead, just a soul wondering the vast universe.

And, if Gojo's Infinite Void made it so that the opponent couldn't attack because they were too overwhelmed, mine made it so that all attacks were mitigated, absorbed by the abyss, the energy saved and ready to be used as a trump card at a moment's notice.

Yep, I was overpowered, but like, didn't I already tell you that like, 7 paragraphs up?

Anyways, this time, I had only used my domain expansion just to check if it was working, so I quickly turned it off and quickly sneaked back to my bed.

Sure, I could have gone practicing, but like, I was only about 6 or 7 judging by the stature of this body, even if it was malnourished and I looked more like a 4 year old, so I had at the very least, 3 more years until Hogwarts would call upon me.

I had also given up sleep already, so I had twice the amount of time that regular humans had to work and train.

As for right now, there was something much more important than anything else…

…and that was planning.

I had already figured out what I wanted to take from this world, so now, I could only plan to take it.

Here I come, welcome me with your arms wide open, this wonderful world of wizardry and magic!