Before the Invasion of Hueco Mundo

 Despite Yamamoto's outward stoic look, that could honestly fool people into thinking that he's asleep, he is concentrating on Ichigo's training with part of his zanpakuto spirit. The older Zangetsu, who Ichigo refers to as Gramps much like Yamamoto himself, is sparring against Ichigo using a quincy blade. Ichigo himself is forced to use his zanpakuto against it to combat the spirit's sword. Uryu is also nearby watching over Ichigo's training with old man Zangetsu, the young quincy had been under the impression that the only weapon that he has is the bow. "Head captain?" Uryu asks, causing the ancient man to turn to look at the young quincy. "You called Ichigo's sword spirit a name that I read in books when I was a kid. Is Zangetsu the Quincy emperor?"

"No, Yhwach Bach is the incarnation of absolute evil. He tried to usurp the world order by slaying his own father over almost a thousand years ago." Yama responds, taking a pause to take a deep breath and let out a long sigh. "It's clear that this portion of Zangetsu is merely the form he chooses to represent his Quincy bloodline."

"Mr tall, dark and moody doesn't say much in our inner world. He actually was protesting against Ichigo ever gaining access to the spirit world. My other half knew that he would always be in danger but danger causes the most growth in the soul." Hichigo responds, having also been manifested when Ichigo himself had brought out Old man Zangetsu to train with. "Five months ago Ichigo was an ordinary boy who could just see spirits and hollows. Now, he rivals even you in power, Head Captain Yamamoto."

"Give him a century or two of practice and you may be right. His rate of growth is something I've only seen in Yhwach himself. Two thousand years ago, he was born a sick child. Blind, frail, sickly, but he had the strange gift to be able to heal those that touched him. Though after they were healed they'd soon die and that health would transfer back to him. Eventually maybe after decades, or centuries he became the father to the quincy bloodline. Everyone who descended from him has been given power but when they die, or when he chooses he gets that power back." Yamamoto explains the history of the Quincy god emperor. "The most troubling fact is that the older Zangetsu had revealed that he is not dead but merely slumbering and that fact troubles me greatly."

"What do you mean when he chooses?" Uryu asks.

"It is an unholy act that he arrogantly calls his 'Holy Selection' those that he uses to perish. It is called the Aushwalen." Yamamoto says, which causes Uryu to swallow a lump of anxiety in his throat.

"All it shows is that he's weak and cowardly, forcing his subjects to gather power for himself then just stealing it away. What a pussy. The only way to gain power worth any amount of respect is through vanquishing your foes and devouring their essence." Hichigo declares vehemently. "Since my queen didn't devour that dead espada, maybe I could get something to eat. Might even gain a significant power boost from it."

"Didn't you just say it was respectable to vanquish your enemy before eating it?" Uryu questions

"Just because my mate doesn't finish her food doesn't mean I'll let it go to waste. While hollows don't typically care for notions like marriage, one of the things a mating pair will do is share a kill. Think of it as a.. Wedding gift." Hichigo explains but the young quincy just looks terrified at the thought. "Do you know if the boys at R&D are done with that corpse already? If Ichigo intends on fighting arrancar, it's only fair that he has the powers of one."

"Disturbing as the thought has been, you may ask them if they're done with the experiments and need to dispose of what's left." Yamamoto responds. "I'm almost interested in the changes it would yield in you since you're the first hollowfied zanpakuto spirit i've ever heard of, let alone met."

"Since you and old man Zangetsu are two halves of the same sword, how come Ichigo doesn't have two blades?" Uryu asks.

"He might later on, powers evolve and change constantly so there's a chance he will have access to wield my other self and me at the same time. Gramps and I are like a coin, one side is one half of his power and the other is the other half. The Shikai is his half of the coin, the tails, and Bankai, my half, is the heads. As they say, heavy is the head that wears the crown. He is the tail since he wanted Ichigo to have never seen, learned or ever gained strength. Whereas I am the instinct, the drive for strength, for power, for domination. Ichigo might wear the crown now, but that doesn't mean that I can't wear one as well." Hichigo explains as he manifests the inverted colored Zangetsu blade in his left hand. "When he is the face, I'm the shadow and shadows can't hurt people." Hichigo says as he swings his blade through Uryu's body harmlessly.

"Hichigo shut the hell up, I'm trying to fight him dammit!" Ichigo shouts, nimbly dodging the blue reishi blade that Old Man Zangetsu slashes at him. "The hells the point of this lesson anyways, Gramps!" He roars indignantly.

"I figured that out ten minutes ago, you really are a hopeless case." Hichigo chides.

"Fuck you."

"We're the same person, dumbass."

"Ichigo, Quincies draw their power from their surroundings. He's using only reishi based attacks, you're supposed to use his own energy against him." Uryu calls out then suddenly it all clicks for Ichigo.

After giving the helpful advice from Uryu regarding the lesson that Old man Zangetsu has been beating into him, Ichigo switches gears from attacking head on to more strategically. Flash stepping out of the way of another strike from Zangetsu, Ichigo appears to the side of the european style straight sword his zanpakuto spirit is wielding. Zangetsu immediately slashes it to the side but in a move that shocks Zangetsu, Uryu and Yamamoto, Ichigo catches the blade in his left hand. The contact with the Quincy weapon causes strange blue veins of power to crawl across his left hand at right angles as they go up his wrist. Clenching his fingers, Ichigo tears the power away from the blade and manifests it in his own hand. Zangetsu stands there disarmed and proud of what Ichigo has accomplished, having stolen away his blade and manifested it in his left hand. The blueish white blade burns with the unstable power of the substitute soul reaper. Its white firelike body just barely holds the shape of a European arming sword, with a back flared hand guard over his wrist and a long flat doubled edged blade.

"What was that technique? I've never seen anything like that." Uryu mutters, seeing the blue veins shrink back into Ichigo's skin as he holds up and inspects the burning blue sword in his off hand.

"It is a technique that Kurosaki Masaki and the Kurosaki quincy clan was very adept at. A protective ability known as Blut Vene. Channeling the spiritual energy from the surrounding world into the veins underneath the skin similar to that of armor or a hollow's Hierro or Iron Skin ability." Zangetsu explains. "Learning how to take an enemy's power from them to reduce the chance of being injured and end the fight quicker."

"There's no fun and no honor in killing a defenseless opponent. It's a coward's way out." Hichigo scoffs seeing his reflection teach Ichigo this technique.

"There's no honor in a fool's death, there is no glory in war. All it is is senseless bloodshed and death. The sooner a fight ends the better, and it is up to Ichigo to show mercy or the finishing blow." Zangetsu retorts. "I am giving him the best possible chance to defeat his opponents and rescue Rukia and protect him, in the end that is all that matters."

"I never thought I would hear you say that, Yhwach Bach. You've never cared for your offspring, only for what they could offer you." Yamamoto says.

"I must remind you that I am not Yhwach Bach. All I care about is protecting Ichigo and his family. My job is to provide what he needs to protect himself and those around him. I will never take anything from him. Only give him the ability to do what needs to be done." Zangetsu responds. "If you're so focused on his return, then allow me to fill you in. In 900 years, he will recover his heartbeat, In 90 his intellect, in 9 years he will recover his strength, and in 9 days, he shall recover the world." When these words leave Zangetsu's mouth, Uryu's glasses crack when a shocking realization hit him.

"You said you fought Yhwach a thousand years ago... if that poem is true it means he's either awake or... gathering strength." Uryu says as he begins to connect the dots. "The Aushwalen kills those it was used on... and my grandfather suddenly lost all his powers when he needed them most. Same with Ichigo's mother. That means..."

"The Quincy king has awoken." Zangetsu says, "It is in our best interest to end this petty war as soon as possible as he is an opponent much more formidable."

"How long do we have?" Yamamoto says calmly. "When did Ichigo's mother die, when did your grandfather die... when did any other quincies perish?"

"July 15th, 1999." Ichigo answers, "My ninth birthday. Seven years ago now."

"We have less than two years to prepare for a war that the Quincy king has been preparing for for a thousand." Yamamoto growls, slamming his staff on the ground and forcing himself to his feet. "Come with me." The ancient dragon storms off prompting both quincies to follow him. Zangetsu and Hichigo return to Ichigo's inner world allowing their wielder to follow his mentor.

Ichigo is mildly surprised to see just how fast his mentor can move, the old man's looks give off an air of ancient wisdom and frailty but that is a trap. Despite his power, Ichigo surmises that he'd need to train continuously for a full century to be able to even scratch Yamamoto in a sparring match, and that's without him using his Shikai or Bankai. He has to flash step three times to just keep up with the head captain, who still beats him to the division twelve research laboratory by almost a full five seconds. Uryu doesn't arrive for another 30 seconds and even then, he stumbles slightly as he comes out of it. "Hhrrumph." Yamamoto grunts seeing the two slow pokes behind him before walking into the laboratory proper.

"Ah, Head Captain. Good afternoon." The ever cheerful Kisuke greets as the head captain and his apprentice enter the room. "What brings you by my lair? Finally going to take up my suggestion on using your sword to power the water heating system?"

"No of course not, I'd never use Ryujin Jakka for such a trivial nonsense matter. I came here because Ichigo needs to strengthen his hollow powers." Yamamoto responds, gesturing to the orange haired soul reaper behind him. "We've come for the dead arrancar."

"I see, I was wondering when this was going to happen. Very well, Mayuri just finished the autopsy on Shawlong. Aside from the brains, you can use what's left for whatever you need, Captain." Kisuke responds as he leads the two through the facility. "We've found out quite a bit about the artificial arrancar that Aizen has created."

"Any weaknesses?" Yamamoto asks, getting straight to the point. "I don't care for their biology, physiology or otherwise, I want to know how to deal with these pests and their insolent master."

"There isn't a general weakness that's common to each of them, but there is one thing we've found that's interesting. Their skin is coated in a hardened type of reishi called a Hierro, or Ironskin which makes it as if they're wearing a suit of armor. Normal soul reapers won't have a chance at cutting through it, and we've tested with a few of the unseated members even all the way up to fourth seat Hanataro. Even after death the hierro is still strong enough to resist sword strikes even shattering a few of the unreleased blades." Kisuke explains, "there is a silver lining, the vizards have been capable of cutting through the hierro with minimal effort, so have some of the captains but they've had to brute force it. Kenpachi, predictably, did it through that method."

"Another case of fighting fire with fire." Ichigo adds.

"Not exactly, it's basically like hitting a diamond with another diamond, only people with hollow spiritual pressure or ridiculous amounts of it can cut through it. They also do not possess regenerative abilities like higher level hollows have, that may differ from arrancar to arrancar, but they only seem to regenerate when they use their resurrection." Yamamoto remains silent as Kisuke gets to a keypad and enters in a lengthy code to enter the elevator to the lower sub-labs.

"Why am I being brought along for this? Science isn't exactly my best subject, I'm a lot better with English Lit. and Grammar." Ichigo asks, causing Yamamoto to arch one of his bushy eyebrows to look at him.

"How do hollows get stronger?" Yamamoto asks sarcastically.

"They eat othe- Ohhhh..." Ichigo goes to answer, then it clicks for him. "I'm gonna need a breath mint after this." Kisuke chuckles to himself hearing the reaction from Ichigo as the elevator opens up into a large surgical theater where the bodies of the arrancar and the single espada are being held.

"So much for this room remaining STERILE KISUKE!!!" Mayuri roars upon seeing the intruders to his lab, the eccentric megalomaniac scientist is dressed in a full surgical gown, head ventilator and veil. "What do you want?"

"It seems manners are still not your strong suit, Mayuri." Yamamoto says taking note of the fact that he wasn't greeted. "Ichigo is going to devour the arrancar specimens to strengthen his hollow abilities." Mayuri goes to make a rebuttal but pauses for a moment.

"Can I make a request, head captain?" The ancient captain raises an eyebrow at this statement permitting the 12th division captain to continue speaking. "I will allow Lieutenant Kurosaki to consume the hollows, in exchange for getting to run a few tests on him."

"Lieutenant?" Yamamoto asks.

"Fine, but no dismemberment and no weird shit." Ichigo says sternly.

"One of the experiments I have in mind would be artificially inseminating my assistant with your genetic info from your arrancar form." Ichigo just stares at the mad scientist disgusted at the question.

"I believe that qualifies as 'weird shit.' Mayuri, and that is not only a question for him but also Kuchiki Rukia as she is his fiance." Kisuke says.

"You humans are strange, carrying notions like empathy, love and kindness. It's disgusting, but fine! I get to keep the brains though."

"I suggest you leave the room then, I don't know if my hollow self can control himself or has table manners." Ichigo suggests, but Mayuri, Yamamoto and Kisuke don't budge.

"Welp. I'm gonna go, bon appetite I guess." Uryu says as he turns and exits the room.

"Oh is it snack time?" White asks from within Ichigo's mind, "Yeah, go nuts, i'm giving you the throne for an hour. After that we're gonna need to figure out the new powers, if we get any." Ichigo says out loud, the three captains look at him quizzically for a moment before he turns and hands his sword to Yamamoto. The ancient captain grabs the weapon from his apprentice as the skeletal mask begins to form over Ichigo's face. Mayuri can't help but shiver slightly, feeling the dramatic shift in the substitute soul repear's spiritual pressure. The mask doesn't stop just over his face however, from the center of his chest a large hollow hole splits open spewing the strange white liquid that spans and covers his entire body. His muscles swell in size, spikes form across his shoulders, a large reptilian tail splits out the back of his shihakusho with red tribal color point markings at the tip of his tail, around his chest and arms. Now standing at nearly 9ft tall, the hollow exhales an evil black gas from its mouth as a wry smile creases his lips. Nemu, who is off in the corner watching the entire event go down, covers her eyes to avoid seeing the mess that's about to take place.