The sheer strength of Ichigo's resurrected form wasn't something that Aizen had anticipated. He thought the boy would be capable of mastering his hollow powers to the point of high speed regeneration, firing ceroes and using the espada's sonido and hierro abilities. However, he never thought Ichigo would not only gain this level of power but also attain resurrection which only arrancar were capable of. Then it hit him, the only possible way that Ichigo would have attained a resurrection would be if his blade was hollow. A hollow zanpakuto, not an inner hollow, Zangetsu it's both his blade and his hollow and that fact scares Aizen slightly. The slight feeling of anxiety in the back of his mind, the unease beating of his heart is distracting to him but he can't help but feel excited for this battle. Despite knowing that he is immortal, he still feels the same anxiety and fear as a brand new academy graduate would feel facing down their first hollow. This however, isn't an ordinary hollow, this is one of his own design, one that he spent the better part of a hundred years preparing, planning and orchestrating the correct events in order to bring about the birth of this entity.
The traitor deflects an incoming blow from Ichigo's left sword before having to dodge to the same side in order to dodge the slash from the next. The ferocity of this monster he created is forcing him onto the back foot, while at first glance it would look like Ichigo had gone feral swinging viciously with both blades like a wild gillain. Aizen notices that Ichigo's slashes all have technique, aim and precision. One blade strikes against Aizen's sword and the other is already mid swing preparing to cut at the opening that will be created behind Aizen's block. He had attempted to catch the black blade in his hand much like he did during their first battle, but Ichigo cut through the carapace, through his flesh and cut the top part of Aizen's left hand off before continuing into his shoulder, almost severing the arm in the process. Trying to regain the offensive, Aizen feints a slash towards Ichigo's chest before flash stepping behind him landing a solid kick on his spine sending him flying forwards towards a partially destroyed building.
Mid air, Ichigo flips to face Aizen before charging another cero between his horns, the black and red beam swirls inwards on itself before expanding and blasting out towards Aizen. The traitor captain raises a hand and casts it to the side casting a kido spell. "Bakudo number 81. Danku." Aizen declares, causing the invisible barrier to form in front of him and stop the cero dead in its tracks. The beam pushes past the barrier around its sides before detonating in the sky, blasting the clouds away. Ichigo stops himself from impacting the destroyed building but is forced to cross both blades in front of him in order to stop the incoming attack from Aizen. The force of the attack sends a shockwave that pulverizes the rubble beneath Ichigo as Aizen presses his blade against Ichigo's swords. The two can't read each other's facial expressions behind their masks but Aizen can tell Ichigo is scowling at him from behind the skull shaped helm of his resurrection. Aizen thrusts his blade downwards, breaking through Ichigo's guard and gashing him across the chest from his shoulder to his hip.
Breaking through Ichigo's grip caused Aizen to over swing, spinning forwards slightly as his blade cut through the left side of Ichigo's hip and shreds through his robes, spraying blood into the air. Ichigo howls in pain before turning a bit more animalistic giving in to his hollow slightly as he growls before headbutting Aizen with his horns stabbing into the traitor captain's shoulder blades. He gouges his blades upwards stabbing Aizen through the abdomen before leaning forwards driving his horns further into Aizen's shoulders then lunging off the air itself launching the two of them towards the ground. He slams Aizen head first into a fire hydrant and then into the concrete sidewalk completely obliterating it. Water sprays from the destroyed fire hydrant, tinged red with blood from both combatants before the ground explodes from another point blank getsuga from Ichigo. A massive crater is formed from this blast, causing several buildings around them to crumble from the explosion leaving nothing but dust and rubble.
From the bottom of the crater two multi vortex tornadoes begin to take root as both combatants begin to recharge their power preparing for another assault. The depth of their power shakes the city of their power like an earthquake. The dust kicked up by the destruction is getting sucked into the twisters forming around them. From above the two combatants looming over the crater, Captain Yamamoto appears from a flash step behind Ichigo, beside him, Starrk, Shunsui, Jushiro, Isshin, Yoruichi and Kisuke also appear to aid in this fight. Behind Aizen only Gin arrives to aid him in the battle to come. Shinji, Love, Rose, Kensei, Byakuya, Hitsugaya and Kenpachi all arrive at the lip of the crater overlooking the abyss created in the fight. The chrysalis over Aizen's body is cracked in the center leading out from the Hogyoku but each of them can sense that it isn't damage from battle, but the next stage in his evolution. "It is about time you arrived Gin, I was beginning to think you were abandoning our mission." Aizen says as he locks eyes with the bull horned masked reaper before him. "I'll deal with the pitiful resistance that the gotei 13 captains are mounting. You're to fight Ichigo."
"Always foisting the hard work on me, you're so cruel Lord Aizen." Gin says in a playful tone before lifting a hand to his face and scratching down. A white and red kitsune mask quickly forms over his face but the reveal of his hollow abilities surprises none of the members of the gotei 13. "Sorry Ichigo, Orders are orders. If it's any consultation, I did like you." Gin says as he draws his short Zanpakuto from its scabbard in his sleeve.
"Kurosaki Ichigo. You deal with the other traitor." Captain Yamamoto declares firmly, realizing how the battle is going to shift. "If we are defeated in this battle today. You are to rebuild the Gotei 13 in our stead."
"Are you really prepared to throw your life away, Captain Yamamoto?" Aizen asks mockingly.
"All of us came prepared to die in battle only to assure your defeat." Yamamoto responds as he draws his blade, the ancient katana igniting into brilliant flames as it makes contact with the air. "This is the line in the sand, Aizen. You will die for your treachery, and for your crimes."
"Your devotion to a dead god will be your death. Genryusai Yamamoto." Aizen responds in a cold empty tone. "As I am the god to replace the soul king. I shall grant you my mercy. Submit to me and you will be spared." He says, boasting to each and every captain that has arrived to stand up to him. "So be it."
As Aizen's spiritual pressure begins to rise, every single captain except for Yamamoto himself and Kenpachi raise a hand to their faces channeling their power revealing the ace among the soul society. With a flick of the wrist, each of the captains summon their masks causing Aizen to become angered seeing this enemy benefit from his research. The grin of Kisuke's marionette mask stares at him with an empty smile, Shunsui's grinning mustache sporting shogun's mask, the dead leaves and bark of Byakuya's, The horned ice spiked maw of the dragon mask that sits over Hitsugaya's face, Shinji's pharaoh mask, the plague doctor mask of Rose, the oni mask of Love, the blast shield mask of Kensei, the plain white mask with three circular marking for Jushiro, and lastly the most irksome of them all, the skull faced mask of Isshin all looking directly at Aizen.
"You old wretch. You stooped so low as to hollowfy your entire captaincy just to defeat me. How low you have fallen, how weak you've become. You're truly pathetic Genryusai Yamamoto!" Aizen declares as the chrysalis around him begins to break apart. The pieces around his face fly off first before his entire body is enveloped in bright purple light. When it dims, Aizen stands in the center of the crater now transformed. The chrysalis form has broken away, partially revealing his face and part of his chest. His eyes are now stained purple in the sclera and his irises a deep silver color. His hair down to his back and as long as Ichigo's in his resurrected form. "I do have to thank you, as I know now what I must do in my new world. The new Gotei that I will craft will serve me and me alone. They will not be such disgusting amalgams of Soul reaper and hollow. They will be true espada. Starting with Kuchiki Rukia."
"Bankai." Ichigo's eyes narrow when he hears Gin say this. The fox masked former captain holding his sword up as if he's shooting a projectile from the weapon. "Kamishini no Yari." He says just above a whisper. The moment the words leave his mouth, a flash of white light appears from his blade traveling at 500 times the speed of sound, his blade expanding to its max length at 1% the speed of light. Ichigo instinctively moved when Gin had spoken, putting his aim off at the last second before the expansion. The blade pierces through the horn on the left side of Ichigo's mask before burrowing itself deep into the earth's crust. The attack shattered half of the armor of his resurrection, and split the white blade he was holding in half as he had raised it when Gin had spoken those words. Recovering from the blow, Ichigo raises his hand and fires a cero at Gin before lunging forwards and vanishing. The bankai blade of Gin retracts just as fast, allowing him to block the attack from behind but it doesn't stop Ichigo from touching the back of his black blade. "Getsuga Tensho." he says Angrily, blasting Gin backwards and right towards the cero he had just fired. However the former captain had studied this technique and dodged the attack allowing both blasts to slam into each other creating a massive explosion.
Gin appears from behind Ichigo slashing at him at insane speeds easily forcing the more inexperienced soul reaper on the defensive. Forcing him to retreat backwards away from Aizen and the other captains. As he blocks another attack, he manages to see Yamamoto ordering the other captains to attack Aizen. This lapse in concentration costs him as Gin slices him across the shoulder on one of the upwards cuts he's making against him. Thankfully his resurrected form allows him to regenerate but he's forced to focus on the fight with Gin. Behind his attacker a massive explosion of golden light appears causing Gin to be back lit as the sly smile of the fox mask stares at him. Gin lifts a hand to the front of his mask motioning for Ichigo to be quiet before Gin suddenly vanishes before kicking him square in the chest sending him further backwards.
With the added distance between them, Gin expands his sword to near its max length again and swings the giant weapon causing Ichigo to block with his forearm and his sword as he's batted away from the fight about to take place with Aizen and the other captains. The force of the blow sends him flying almost halfway across the fake city and through several buildings before being pursued by Gin. In the distance, Ichigo can see Yamamoto direct his sword forwards commanding the other captains to attack Aizen. Gin pursues the resurrected Shinigami through the city continually shooting his blade at him dozens of times in a second forcing Ichigo onto the defensive as they get further and further away from the battlefield. However, Ichigo can sense that each of the attacks isn't being targeted for vital organs, instead they're being placed to look like they're going for vitals at a distance, but also keep them close enough so Ichigo has to dodge them. Finally, almost a mile from the battle Gin stops and lands on the center of the street allowing Ichigo to recover.
"What gives?" Ichigo asks, sensing the jig is up, "Why did you interrupt us, I almost had him."
"You were going to die." Gin says as he removes his mask from over his face. "I had to make it look convincing, but as you are now you cannot defeat Aizen. Not anymore." he warns prompting Ichigo to grit his teeth in anger.
"So what? Am I supposed to just let him walk out of here?!" Gin nods his head at this question which dumbfounds Ichigo. "I need you to explain just what the hell is going on dammit!"
"He hurt Rangiku, back when we were children. I've spent 200 years plotting to defeat Aizen and I need you to play along." Gin explains. "We need to let Aizen defeat them. Once he gets to the human world, I'm going to reveal the true power of my bankai and kill him. Kamishini no Yari kills with the venom of a serpent. One strike is all it will take to destroy him completely. But, if he senses my betrayal I want you to promise me this. Promise me that you'll take care of her." Gin pleads, causing Ichigo to tilt his head down as he approaches Gin.
"I can't." Ichigo says, causing Gin to look saddened by this for a moment, but that's all he gets as Ichigo punches him in the stomach and then chops him on the neck with his full strength. As his consciousness is fading, he hears Ichigo speak to him again. "Take care of her yourself. I'm not letting anyone else die." As he's about to leave he sees Gin holding onto something in his other hand. As he crouches down he notices that Gin is holding a small black bracelet and a note in his hand.
"Rangiku, if you're reading this. Please don't mourn for me. I did terrible things in my desire for revenge. I just hope you can forgive what I've done, and I hope to see you in the next life."
-Gin
The bracelet he's holding is one that Ichigo recognizes, it's a reishi concealing device that Gin was planning to use in order to assassinate Aizen. He glances at the bracelet for a moment before attaching it to Gin, feeling his reiatsu vanish in a second making it seem like Gin had died in their engagement. In the distance, he sees another massive explosion blotting out the sky with purple light and black smoke and he can feel that the other captain's spirit energy is diminishing rapidly. Gathering all his strength he lunges as hard as he can pushing his sonido to its limits causing the muscles in his thighs and legs to scream and burn from the strain. The result is a solid after image that stays for almost five full seconds before vanishing causing a sonic boom to emanate from the position where it once stood. Despite them only being a mile from the fight where Aizen and the captain's were going down, it feels as if he cannot move fast enough to get there in time. He sees his comrades laid out, defeated and unmoving in the destroyed street as Aizen looms over Yamamoto who is lying flat on his back. "You have failed, Kurosaki Ichigo." Aizen says as he turns and locks eyes with the young shinigami. "Bow before your new god." He says before teleporting above him and stabbing him through the back pinning him to the ground. The strike shattered his resurrection, causing him to drop out of Bankai as he screams in pain. Aizen twists the blade to the side slightly, further gaping the hole in Ichigo's left lung, and cutting into his heart slightly. "If you move, you will die. That gash nicked your heart and too much strain will cause it to rupture. You'll survive long enough for Orihime to heal you, but by then I will sit as the new Soul King. Goodbye Kurosaki Ichigo." Aizen says as he pulls the blade from Ichigo's back and turns to walk away. With the wave of his hand he summons the rice paper and wooden portal door of the Senkaimon before walking through it. As it closes, Ichigo begins to lose consciousness. The last thing he sees as his vision begins to fade is Captain Unohana and Orihime arriving to tend to him.