After my nightly 'purging', I went to the most out of the way park I could find. I didn't know what would happen, but I also didn't want to risk my apartment exploding.
I'd experimented with manipulating ambient energy before, enough to know that it was different than what I used to know. I settled myself into a comfortable seated position on one of those cage-climby things for kids and began drawing in whatever ambient energy there was.
There was more than I'd expected, but less than I'd hoped for. I let my mind fade to the sensations of my body, carefully monotoring the interaction between it and the energy. I wasn't exploding, so that was nice. What wasn't nice, was I couldn't feel a pull to my core.
One of the first things a cultivator does, after foundation building, was to pull energy into their core, or 'dantian'. Essentially, this is a way of extending the body's stamina while also training the cultivator in how energy moves through the body. It's also it's own major foundation building.
The core is effectively a limited storage for energy, once its full it won't accept any more. That was beyond critical for later stage cultivation. By forcing more energy into the core, it condensates into a denser, more powerful energy source. That new source, is the building block of all the end tier cultivation techniques.
Except, I didn't have one anymore. No core meant no way forward... or so I thought. In my slight panic, I managed to sense that my body was still storing the energy, just not in a core. Every cell was drinking up as much as it could, as if dehydrated. It was slow, but I could feel that the cells were becoming stronger as they saturated themselves.
In spite of this new revelation, I couldn't help but revisit a thought I'd been having sense waking up in this world. 'Is cultivation even possible here?'
No, certainly not in the same manner I was used to, at least. Still, that didn't mean there wasn't a way forward. I contented my self in sitting on the barred surface for a few hours. It was a process that would certainly take more than one night to complete.
[...]
"Good morning Tatsuki, Orihime, Rukia... wait, since when does Rukia walk with us to school?" I greeted my group of friends.
"Since when do you?" Tatsuki retorted, alluding to my recent absence from the group. I'd spent most nights saturating my body with energy at the park, as a result I didn't typically wake up early enough to walk to shool with my group of friends. I'd skipped the previous night's session, choosing to take friday and the weekend off. "Rukia's basically been part of our group sense she got here. Where have you been?"
"Ascending mortality." I 'joked', something I often said in responce to them questioning my supplement 'addiction'. "What have the lowly mortals been doing this past week?"
"Oh, shut up Arashi." Tatsuki retorted.
"Hey, did you see the new episode of Cazh Soul? Don Kanonji was at an abanded hospital! I think he's moved on from prisons." Orihime excitedly went on about the fake spiritualist. Most of the group didn't like the show, but we supported our friend.
We were joined by Chad and Ichigo shortly before we reached school. We got to class and I settled in to enjoy a peaceful break from training.
[...]
"What even is today?" I questioned reality, watching Ichigo fight... the air? Honestly, I knew that there was something there, because whatever it was knocked into the desks, but I couldn't see anything.
Ichigo hadn't faught any spirits, from what I could remember, so I was confused. But, as I was focusing on the spot where the desks were moving, I thought I saw... "Ichigo?"
While I was trying to adjust to what I was seeing, Ichigo in a black robe-thingy fighting school uniform Ichigo, both Ichigos fled out the window and Rukia fled the classroom. Whatever was happening, my old cultivator's curiosity wouldn't allow me to ignore it, so I jumped after the Ichigos.
It was a three story drop, but I'd been strengthening my body with energy for the past week. As any decent cultivator would know to do, I started with my bones. Specifically, the key points of support for my body. As such, it only hurt a little as I landed in a roll and ran after the school uniform Ichigo.
'Damn, maybe I shouldn't have skipped last night...' It may have hurt more than a little.
My speed, much to my aggravation, wasn't a match for the Ichigos', but it was enough to keep in sight of them. They ran in a rough half circle from Karakura High to Karakura Middle School.
Their chase was interupted by a large snake-like monster, but by the time I made it up to the roof, black robe Ichigo had sliced into it's face. Oh, and school uniform Ichigo was falling from the roof.
"Dammit Ichigo!"
[...]
That night, I redoubled my efforts to absorb more energy. Ichigo had Rukia do something to my memories. It was weird, I still remembered everything that happened, but I also could clearly remember a different series of events. Now, I knew a couple of important things.
One, Ichigo was somehow involved with fighting spiritual monsters. Two, Rukia was likely the cause of it. Three, I was sullying the image of cultivators by letting a literal teen out pace me. You know what didn't help? That the ambiant energy wasn't being absorbed as fast as before.
"What the hell?!" I exclaimed in frustration, letting myself fall back onto the bars.
"You're not a Quincy," I rolled back and readied myself for a fight in reflex, only to see Uryu Ishida from my class. "and you're certainly not a Soul Reaper. What were you even trying to do?"
I stood watching him and calming myself before I decided to answer. "Strengthen myself with the ambient energy." I answered with the same exuberance I gave my friends about the 'supplement' addiction.
"I see. Then you're an idiot." The jerk pushed his glasses up his nose before continuing. "Reishi can be directed and absorbed, true. But you can't expect to do that if your spirit energy is actively pushing against it."
"Reishi? Spirit energy?" I asked dumbly. "I assume you mean that Reishi is the ambient energy, but what's spirit energy?"
"I don't have the patience to explain it to you in depth, but I suppose a barebones explanation would be appropriate." Uryu sighed. "You assumed correctly about Reishi. Reiryoku, or spirit energy, is generated by the Hakusui or Soul sleep. There are many factors that determine the strength and output of your spirit energy, but it's mostly a control issue in your case.
Reishi and Reiryoku are compatible, but can't normally take up the same space as one another. That's just physics."
The helpful jerk vanished after his little lesson, leaving me to self analyze. If I was having trouble absorbing Reishi, then I was producing more Reiryoku. The only thing I could think of that might have affected me was my close proximity to the monster that Ichigo destroyed. "This is giving me all sorts of 'opportunity' vibes."