Hueco Mundo
A fatigued Ichigo kneeled on the ground with blood dripping down his face and half of his Bankai's Shihakusho missing. On the ground next to him was a small green haired hollow girl, lying face down in the sand, unconscious. In front of him, was the lifeless corpse of an Espada with long black hair.
"Nel...I couldn't have beaten Nnoitra without your help…" Ichigo commented as he stared at the Espada in front of him. After defeating Grimmjow with relative ease, fighting Nnoitra soon after was too much for him alone, resulting in Nel transforming and fighting alongside Ichigo.
"The hell?! You didn't save a strong guy for me?" A voice said from behind Ichigo. Ichigo turned around and saw Kenpachi walking slowly towards him with Yachiru on his back.
"K-kenpachi? Why are you-" Ichigo's question was cut off as Kenpachi swung his sword at Ichigo. Ichigo narrowly dodged the hit and tumbled back in the sand.
"What the hell was that for?! You could have killed me!" Ichigo exclaimed.
"Well who the hell am I supposed to fight?" Kenpachi complained. As he began walking towards Ichigo they both sensed a massive reiatsu appear next to them in an instant.
"I'm going to borrow these two." Starrk said as he picked up both Nel and Orihime before Ichigo and Kenpachi had time to react. As fast as he had arrived, he quickly left, using his Sonido.
"DAMMIT!" Ichigo yelled as he attempted to run after him but immediately fell forward onto the sand unconscious.
----
Several hours later
Ichigo woke up to a warm feeling surrounding his body. As he opened his eyes, he saw the face of Unohana hovering over him as she healed his injuries and restored his reiatsu.
"W-where's Inoue...and Nel…" Ichigo grunted as he tried to get up.
"You need to relax, Kurosaki. Wait until I'm finished healing you." Unohana responded.
"No...I need to…get them back…" Ichigo said as he struggled to get himself up.
"Go back to sleep, Kurosaki." Unohana replied in a serious tone but still maintained her calm smile. Ichigo felt a shiver travel down his spine as he looked at Unohana's face and immediately went back to sleep.
Another hour passed and Ichigo woke up. Most of his wounds were healed and his reiatsu was restored. He immediately sprung up from where he was laying down and looked around.
"Kurosaki, while you were knocked out, Aizen made an announcement. He is going to invade Karakura Town. Inoue and Nelliel are being held at the fifth tower. It also appears that the four of us Captains who came here to Hueco Mundo are now trapped. Currently, Captain Kurotsuchi is working on a solution to reopen the Gargantas." Unohana said.
"Dammit…" Ichigo responded, clenching his fists and looking at the ground. "If we're unable to go back to Karakura Town...then the least I can do is save Inoue and Nel!"
Before Unohana had a chance to say anything else, Ichigo vanished from sight.
----
"Inoue! Nel!" Ichigo yelled as he entered the tower. He continued walking through the tower, yelling their names with no response. As he reached the upper floors of the tower, he sensed a massive reiatsu waiting for him.
"So you made it up here ya little pipsqueak!" A large Arrancar walked out from the shadows. He had tan skin, a ridge lined skull, and fragments of his hollow mask encasing his lower jaw.
"I don't have time for you Yammy!" Ichigo yelled as he drew his zanpakuto.
"Bankai!" Reiatsu swirled around Ichigo, covering him in a black dome. As the dome vanished, Ichigo's massive sword was replaced with a sleek black one and the top half of his shihakusho was replaced with a long black coat.
"Tensa Zangetsu."
"This again? Don't waste my time!" Yammy retorted as he began charging at Ichigo. Ichigo suddenly vanished from his sight and reappeared behind Yammy, forming a large gash in Yammy's back as blood began to shoot out from it.
"You little…" Yammy said as he turned around, veins starting to pop out on his face. His reiatsu began to flare up as he took a step forward, only to stop as several bright blue arrows landed on the ground in front of him.
"Ishida?!" Ichigo exclaimed as Uryu landed on the ground.
"I can deal with him. You need to go and get Inoue." Uryu said as he aimed his bow at Yammy.
"Thanks!" Ichigo replied quickly before vanishing from the spot as he continued to travel up the tower at full speed in his bankai.
In nearly an instant, he scaled the tower, making it to the top floor. Ichigo stood in awe at what he was seeing. In front of him was Orihime, unconscious on the ground. Standing above her, was Nelliel, but instead of her child like form, she was in her ȧduŀt form. Her green rags were replaced with the standard white arrancar attire.
"Nel...what the hell is going on here…" Ichigo questioned.
"Lord Aizen has reopened my eyes and given me a second chance to prove myself to him. In order to do so, you must die here, Kurosaki Ichigo." Nel replied coldly.
Ichigo gripped his sword tightly as he looked into Nel's eyes. The once cheerful eyes of the little arrancar he had befriended were gone and replaced with cold lifeless ones.
"Nel...snap out of it!" Ichigo yelled, becoming frustrated. Without saying another word, Nel drew her sword and vanished from sight, reappearing in front of Ichigo and swinging her blade at him. Ichigo blocked her blade with his own.
"Don't let Aizen control you like this!" Ichigo yelled as he pushed Nel back. "You have to remember Nel!" Ichigo continued.
"I exist only to serve Lord Aizen." Nel replied before vanishing then reappearing in front of Ichigo. She delivered a swift kick to Ichigo's ċhėst, knocking the wind out of him as he was sent hurtling upward through the top of the tower where the blue skies of Hueco Mundo were now black like the night sky.
"Nel...I don't want to fight you like this!" Ichigo said as he put his hand over his face. Black reiatsu began to form over his face as tears started forming around his eyes.
"Declare, Gamuza." A bright burst of spiritual energy covered the night sky, lighting it up with bright pink rays. Her lower body began to morph, taking the form of a centaur as the horns from the mask on her head grew in size.
"Aaaaghhh!!" Ichigo yelled as he summoned his hollow mask over his face. Ichigo looked up at Nel's figure with the moon behind her. The power of her form felt greater than when he and Itachi had fought Ulquiorra's first resurreccion.
Suddenly, Nel disappears forms Ichigo's view and reappears in front of him with a white lance in her hand. She jabs at Ichigo in a quick flurry as Ichigo tries to react. Ichigo manages to parry a few of the jabs but several cuts begin forming around his body as the jabs keep coming at him.
"Getsuga Tensho!" Ichigo yelled as he channeled his reiatsu into his sword and swung it at Nel's lance, resulting in a large explosion of black reiatsu and dust. Ichigo quickly jumped out of the dust cloud, only for Nel to swing her lance, clearing the dust entirely and revealing her body completely unscathed by the attack.
Ichigo looked at Nel in shock. He hadn't used his full power in the attack as deep down, he still didn't want to fight Nel, but at the same time, he realized their power difference.
Nel suddenly charges at Ichigo, with Ichigo bȧrėly managing to block the tip of her lance as he gets sent flying back into a pillar with her lance pressed hard against his blade.
"Nel snap out of it! This isn't you...I don't want to fight you!" Ichigo pleaded as he tried to keep Nel's lance from piercing his body. Nel remains silent but responds by flaring her reiatsu and pushing Ichigo through the pillar.
"Kurosaki. Do you lament the fact that you are unable to save the friend you once knew...or do you lament at your own powerlessness?" Nel asked as Ichigo stood up from the rubble of the pillar, with half of his mask now cracked.
"No...I am strong enough to save you!" Ichigo retorted as he swiped his hand across his face, rejuvenating his hollow mask.
"I see...if that is your answer, then I will prove you wrong." Nel responded as she raised her lance straight up.
"Resureccion: Segunda Etapa."
A dark pink burst of reiatsu covered Nel's body as Ichigo watched in horror. Her reiatsu was greater than before, surpassing what Ichigo had originally sensed when Itachi was fighting Ulquiorra's second resureccion. The remnant of her mask that was on her head was now gone with only the horns remaining. The horns that were once white were now a dark shade of brown. Her upper body was now bȧrė with patches of light brown fur covering parts of her brėȧsts and her sides. Several pink markings glowed on her ċhėst, shoulders, and abdomen. The light colored fur of her bottom horselike body was replaced with a darker brown, transitioning to lighter patches around the legs and underside. Her once purely white lance had lost its physical form, being replaced by only a handle emitting bright pink reiatsu in the form of a lance.
"What did Aizen do to-" Ichigo's words were cut off as Nel pierced through his ċhėst. Ichigo's mask shattered immediately as he coughed a large amount of blood. His eyes grew lifeless as Nel removed the lance out of his ċhėst.
"Nel.." Ichigo said as he fell to ground lifelessly.