Soulbound

The throne room was gigantic and its high ceilings disappeared into darkness. Roughly woven curtains lined the walls, which appeared to wick away any light that tried to seep through from the stained glass windows. There were torches around the stone pillars which threw uncanny shadows onto the floor. The atmosphere was heavy with oppressive energy as if the room itself was holding its breath.
Khajiit Dale Badantel stood before me, wearing his customary carmine robes. Those cold eyes of his looked at me with a hint of a smile playing on his lips. I sat comfortably near him, trying to calm my nerves and contain the mana within me. My 'heart' or whatever it is, throbbed in my chest, but I couldn't tell whether it was because of anticipation or pressure exerted by dark energy present throughout the room.
"So, master. You want to learn how to manipulate dark energy. Please remember It's not like the white mana you're used to. This stuff is wild, hungry, and it'll tear you apart if you're not careful."
I nodded in acknowledgement, indicating my comprehension.
He sniggered and flipped his hand open to me as a sign for me to start. Because he was a necromancer while alive, he should be the most proficient and the best guy among all these people here who can teach me how to handle this new class. When he said that he could manipulate all this stuff, I asked if he was willing to teach me. Even if he had lost all of his own strength, he still retained his knowledge.
All of a sudden, the air surrounding me became dense, like standing in a storm just before it broke. I felt that swirling dark energy flickering around, ready to burst out at any instant. It was nothing like what I had tried testing, which is mana's calm and steady flow. This was utterly pure chaos boiling inside, which would eat me once I made a wrong step.
"Don't try to control it. You can't force dark energy. You have to guide it, let it flow through you, and give it direction. Think of it like a wild animal. You don't tame it, you work with it."
Khajiit said, his tone almost bored, like he'd done this a thousand times before, which, to be fair, most likely happened.
I took a deep breath and extended my hand, reaching out with my mind to touch that chaotic storm. It responded instantly, lashing out like it had been waiting for me to make the first move. Pain shot up my arm as the energy flared, wild and uncontrollable.
"You've got to feel it out, let it know you're in charge, but don't try to crush it. It'll only fight back harder."

I clenched my jaws and attempted to unwind myself, allowing the power to surge through me without requiring it. That is, it was like having a firm hold on a raging river. However, I found out that if I let myself be carried by this current instead of trying to swim against it, it would carry me along with it.
"Now, direct it. Give it purpose. Focus on what you want it to do."
Concentrating on the energy swirling inside me. I imagined it like a blade, sharp and deadly, something that could cut through anything in its path. The dark energy responded, coiling around my hand, crackling with power.
"Now, unleash it."
I didn't hesitate. With a sharp motion, I thrust my hand forward, and the dark energy exploded out of me in a jagged bolt of black lightning. It tore across the throne room, slamming into the stone wall with a deafening crash. The impact left the wall cracked and smoking, chunks of stone falling to the ground with a heavy thud.
Thankfully, the wall repaired itself; every chunk levitated back into place as if time was reversed. I noticed that after accidentally scratching one of the pillars, it was repaired in a matter of seconds.
The room was silent, save for the distant echo of the blast. Khajiit watched me with a satisfied look in his eyes, like a teacher whose student had just passed their first test.
"Great work, my lord, but remember, this is just the beginning. Dark energy isn't something you master in a day. Now, if you would excuse me."
With that, he left me here while I decided to try on something I did when just starting. I got around a tenth of the spiritual energy or whatever that is from inside of me and willed it to leave through my hand. This time, however, there was a lot of this energy compared to the minuscule amount a while back; the same could be said about the control I have of this energy. Previously, it barely listened to me, and it was hard to manipulate it, but now it's easy, actually.
When the energy left, something weird happened. It actually took the shape of a sword, a katana, to be exact.
Is that the zanpakuto my wielder is having but more... physical?
I thought while looking at the slightly levitating weapon made purely out of some ghost matter. I grabbed it and noticed that I could interact physically without a problem with it while, at the same time, it was light, like almost weighing nothing. This is not a good thing because it might not have any impact on the opponent due to a lack of force from the weight. To test it out, I threw it around the room and saw it travel like a bullet and impale itself on the wall, leaving cracks around the impact zone.
I think it's only weightless for me.
I honestly doubt that Atsune also has this blade in such a form. It most likely resembles a normal katana without weird features with its weight.
I took it back from there, which was harder than I thought since the blade got deeper into the wall than I had thought. After taking it out, the wall repaired itself as usual.
A sudden thought entered my mind that maybe I could change it into shikai form.
So, wanting to achieve just that, I put more of the energy into the blade. It took more than half of the remaining amount, which is a lot. I don't even want to imagine how much bankai would require, even if it will take way longer to get to that point. From my knowledge, the bankai was impossibly harder to achieve than the shikai, which makes me wonder at what tier it will unlock.
The transformation finished once nearly all my reserve was emptied. The whole zanpakuto was covered in mist and I couldn't see it, even then I was able to grab it and got shocked. It was heavy. Not too much, i could still use it, but compared to weightless sword it is a huge change.
The smoke or mist surrounding it dispersed, revealing the new weapon that I had in my hand.
Huh? A naginata?
Yes, the weapon I saw was a naginata, but compared to the normal ones, it looked different. Its blade looked made out of pure energy and was turquoise in colour, with some runes engraved on the blade. The handle was wholly made of silver-coloured metal with some engraving around it. The weapon was actually a little bit taller than me, which is a lot. Thankfully, looking at my wielder, who reaches the height around Zaraki, she won't have much problems with it.
I hold it in one hand and gave it a few calsual swings around. Yeah for now I wuill need two hands, I am not competent enouth to do it with only one. For now, I will have to learn how to do it from someone, but welp, there is no one who can help.
It will have to wait for some time until someone good with this kind of weapon appears.
I seem to know what are the abilities of the shikai or rather an ability. For now, there is just a single thing that is a passive effect of shikai. That is the fact that it is not only cutting the body or spiritual matter that the opponent is made of but the core of theirs. In short, it stops regeneration. If you get cut, your soul is also cut at the same place, which means that your body will not be able to heal unless you repair that first. It happens because the body is always trying to reach the form identical to your core, so if 'the template' has a cut, then it will be copied.
I stayed swinging a weapon around to get a feel for it and realised that making it stay in this form is draining energy all the time. I de-summoned it and stoped playing around.
I also started contemplating if it would not be a bad idea to tell my wielder what might happen in the future. I mean, thanks to Baldie appearing, I now know what point of the story we are in now.