"Remember, don't you dare go out lately. I don't want our next meeting to be through prison bars." Kensei stared intently at Aizen's glasses, trying to see past the reflective lenses to gauge his expression. "If you're particularly unlucky, I might even have to collect your corpse."
Seeing Aizen nod repeatedly, repeatedly promising he wouldn't go out, Kensei finally relaxed—halfway, at least. But worrying too much now was pointless anyway; Old Man Yama had said they'd deal with the mysterious person (Aizen) after finishing off the rebels.
Once he was fully prepared, he'd descend like a divine soldier to save Aizen's sorry hide when he was in trouble. That would surely move him to tears, maybe even make him call Kensei 'daddy'.
Seemingly lost in the image of Aizen clutching his leg and calling him 'daddy', Kensei burst into unrestrained laughter.
Aizen ignored Kensei's sudden fit of madness. He pushed up his glasses, his eyes gleaming with contemplative light.
Kensei had emphasized so many times not to go out. Either he genuinely cared, or... he had guessed the mysterious person's identity was Aizen himself. But he'd been recovering from his injuries recently and had never been to the Rukongai. How could he have possibly figured it out?
Aizen mentally reviewed every detail of his interactions with Kensei since starting his experiments. Finding no flaws, he grew even more perplexed.
Could Kensei have placed some undetectable tracking-type Kidō on me?
Unable to reach a conclusion for now, Aizen gave up overthinking it. For the moment, knowing this家伙 wouldn't harm him was enough. Unfortunately, his recent experiments had reached a critical stage. Breaking through the current bottleneck would bring him one step closer to completing the Hōgyoku.
"Hey! What are you thinking about? You didn't even react when I was talking to you!"
Lost in thought, Aizen was suddenly jostled by Kensei.
"Nothing. Just got distracted for a moment."
"Alright. Let me ask you again, then. Want to learn 'Ikotsu' and 'Sōkotsu', the techniques I comprehended from Old Man Yama?"
Aizen was very tempted. Unlike Shunkō, which had rather distinctive characteristics, a technique like Ikotsu had sufficient power and could nicely compensate for his current lack of high-output attacks.
"State your terms."
Aizen didn't believe Kensei would offer favors for no reason. Even if there were no conditions now, there surely would be later.
"Hehe, you have to promise me you'll go to a certain place for me in the future and help me find some... people."
"Agreed."
Though he had a feeling Kensei's smile was somewhat malicious, the condition held little difficulty for Aizen. He probably just wants me to go to the World of the Living.
Would Kensei go to the World of the Living? Of course he would. But this time, the place he mentioned was Hueco Mundo. Thinking about the explosive figures of post-arrancarization Halibel and Nelliel, Kensei felt it was time to take the first step towards his Hueco Mundo dream. The rest would have to wait until Aizen completed the Hōgyoku. After all, it was hard to get interested in non-arrancarized Hollows.
Both thinking they'd gotten a good deal, the two went to their usual training spot to begin Ikotsu practice. Though using this public training ground was still somewhat inconvenient. Gotta get a secret training ground when I have the chance.
"Originally wanted to teach you Shunkō too. Didn't expect you, Aizen, to have such short-sighted taste, looking down on that technique. Pity you'll never experience the thrill of combining Shunkō with Sōkotsu to one-punch a Captain."
Watching Kensei shake his head and sigh, putting on an act of 'you don't know what you're missing, you're losing out', Aizen mercilessly exposed Kensei's black history.
"Then end up like you, with both arms unable to move?"
Kensei's face flushed red. He began to argue loudly with phrases like, "Injuries a Shinigami gets killing enemies can't be called injuries, they're honors!" and "When I perfect it, even if you beg me, I won't teach you!"—all sorts of things Aizen couldn't quite follow.
Admittedly, Aizen's talent was indeed impressive. Teaching him Ikotsu was far easier than teaching Soi Fon. It took Soi Fon nearly a week to barely grasp the know-how, while Aizen was already getting started after a few hours.
"Sōsuke, this teacher has nothing more to impart to you. You may leave the mountain now."
Kensei looked at Aizen with relief, his tone both vicissitudes of life and full of expectation, like a father watching his son grow up.
Aizen understood the profound meaning in Kensei's gaze. Moved, he responded by using Ikotsu to slam an attack toward Kensei.
"Whoa! Sōsuke! You dare use my own move against me?!" Kensei instantly threw a punch, striking later but arriving first, shattering Aizen's Ikotsu. "Useless, useless! Your Ikotsu has only reached the first heavenly stage, while mine is at the ninth!"
Aizen knew Kensei was intentionally holding back to help him refine his Ikotsu. Otherwise, with the quality of Kensei's spiritual pressure, a serious hit would have sent him flying long ago.
"Hmph! Is this all you've got, Sōsuke? Weak! Weak! Weak!"
The shadows of their fists constantly crisscrossed, looking from the side as if both had grown several extra arms. The collisions of spiritual pressure caused the surrounding ground to continuously dent and shatter, the resulting shock wave kicking up clouds of dust and gravel.
Aware that his Ikotsu was continuously improving, Aizen felt genuinely grateful to Kensei. Though it would be even better if this guy could just shut up during a spar. I wonder if he's this noisy when fighting others too.
His head already aching from Kensei's noise pollution, Aizen proactively withdrew and called a halt to the lesson. Honestly, Aizen's ears were still ringing. He'd rather go toe-to-toe with Captain-Commander Yamamoto than endure Kensei's ghost noise again. At least Yamamoto would give him a quick end.
"We're stopping already? I wasn't even warmed up."
Kensei seemed somewhat unfinished, feeling that after his recovery, his physical qualities had improved. Do I have some kind of Saiyan physique? Getting stronger from near-death experiences?
"Oh, right, Sōsuke. Tomorrow I'm going to thank Sister Flower. What do you think I should bring?"
Walking side-by-side with Aizen on the way back, Kensei asked casually. After all, Sister Flower was the one who found the Hell Spring to heal him; thanking her was the right thing to do.
"Captain Unohana is deeply fond of swordsmanship. If you spar with her using Zanjutsu, she would undoubtedly be very pleased."
"Let's skip that one. Any other ideas?"
Just thinking about Sister Flower wielding a sword made Kensei shudder a little. It wasn't that he was afraid of being completely outmatched, but Sister Flower had too much stamina. Once she got into it, she could go not just for a day, but for three days and nights without rest. Kensei was afraid he'd be completely exhausted after one bout with her.
"She likely prefers food with strong flavors. Just make something and bring it."
"How do you know that?"
Aizen fell silent. He couldn't very well tell Kensei he'd overheard it. Since this guy probably wouldn't press the issue, he simply didn't answer, leaving Kensei to figure it out on his own.
"Sigh, troublesome!"
The mere thought of facing Sister Hana made Kensei feel the future looked dim. She looks so gentle and beautiful. Why does she have to be a sword maniac?
Watching Kensei return to the dormitory, sitting on his bed still looking troubled, Aizen couldn't help but think this guy was bound to get into trouble because of women sooner or later.