|Previous Affiliation||Aizen's Army|
|Occupation||King of Hueco Mundo|
|Previous Occupation||Sexta Espada|
|Previous Partner||Shawlong Koufang, Edrad Liones, Di Roy Rinker, Nakeem Grindina, Ylfordt Granz|
|Base of Operations||Las Noches|
Grimmjow, like his master and fellow Espada, was present when Ben Tennyson showed up in Las Noches. Like everyone else present, he was quite surprised when Ben used the Ultimatrix to transform into Humongasaur (and then Ultimate Humongasaur) to battle Yammy. After Aizen convinced Ben to serve him, Grimmjow introduced himself to Ben, who was slightly put off by the Espada's punkish appearance and demeanor.
After Ben used NRG to damage Nnoitra Jiruga and leave him with several burns, Grimmjow mocked the Quinto Espada, taking amusement in his pain and humiliation. When Ben used Way Big to hand Nnoitra an overwhelming and painful defeat, Grimmjow was visibly shocked and amazed.
First Battle with Ichigo KurosakiEdit
After Ulquiorra Cifer chose to spare Ichigo Kurosaki's life in the belief that he could never be a threat to Aizen, Grimmjow, who thought otherwise, went to Karakura Town in the dead of night with his Fraccion and attacked Ichigo and his friends. Though his Fraccion were all killed, Grimmjow fought Ichigo himself and overpowered him, despite receiving some damage from Ichigo's Bankai. However, he was forcefully taken back to Las Noches by Kaname Tosen, who severed his left arm and destroyed it using Kido. As a result, Grimmjow lost his Espada position.
Ben Tennyson, upon learning of this, was visibly shocked and offered to reattach the arm using Swampfire, much to Grimmjow's surprise; unfortunately, since Tosen had destroyed it with Kido, the arm could not be reattached.
Second Battle with Ichigo KurosakiEdit
With the position of Sexta Espada now vacant, Aizen offered it to Ben Tennyson, but Luppi Antenor protested and challenged Ben for the position. Ben, having already humiliated Luppi in a previous fight, easily defeated him again, but turned down the position in favor of remaining as one of Harribel's Fraccion. Luppi got the position, but every time he tried to gloat about it, those around at the time, including Grimmjow, would quickly point out that Luppi only got the position because Ben didn't want it, much to Luppi's fury. Grimmjow himself preferred that Ben would replace him, likely due to the latter's power.
During another assault on Karakura Town, Grimmjow had a rematch with Ichigo, who had gotten stronger through training to control his Inner Hollow. Despite having only one arm, Grimmjow put up a surprisingly good fight, and was finally able to gain the advantage when Ichigo's Hollow mask shattered, only to be interrupted by Shinji Hirako, who pushed Grimmjow into a corner. He attempted to release his Zanpakuto in a fit of rage, but was interrupted by Ulquiorra and forced to return to Las Noches, angering him even more.
Regaining his PositionEdit
Back in Las Noches, Grimmjow was present when Aizen asked a recently kidnapped Orihime Inoue to demonstrate her powers. She did so by restoring Grimmjow's arm, much to his shock. Tightening his now restored fist, Grimmjow told Orihime to restore his Espada tattoo (which had been covered up since his demotion). After she complied, he quickly and viciously impaled Luppi through the chest with his restored arm, then incinerated the top half of the dying Arrancar's body with a Cero. Standing over Luppi's corpse, Grimmjow let out a crazed laugh and elatedly announced his restoration as the Sexta Espada.
Invasion of Las NochesEdit
Third Batle with Ichigo KurosakiEdit
When Ichigo, Yasutora Sado, and Uryu Ishida invaded Las Noches with the intention of rescuing Orihime, Grimmjow became determined to settle the score with his rival. He got his chance when Ichigo contronted Ulquiorra. Grimmjow intended to interfere, but to his surprise and amusement, he didn't have to: Harribel, who had betrayed Aizen on Ben's behalf, had beaten him there, having been asked by Ben to deal with Ulquiorra. Grimmjow challenged Ichigo, which the latter accepted. Ichigo released his Bankai, and Grimmjow responded by releasing his Zanpakuto, unleashing his Resurreccion. After exchanging a few words, the two battled.
During the course of the battle, Grimmjow noticed that Ben Tennyson, along with Nelliel Tu Odelschwanck, Sado, and Uryu, were watching. Laughing mockingly, Grimmjow revealed that Harribel and her Fraccion had fallen in love with Ben, much to the latter's surprise, before continuing his fight with Ichigo. Ultimately, Ichigo overpowered Grimmjow and knocked him unconscious.
Return & Battle with Ben TennysonEdit
At some point after his defeat, Grimmjow was healed by Retsu Unohana on the request of Professor Paradox. Eager for another fight with Ichigo, Grimmjow opened a Garganta and headed for Fake Karakura Town. When he arrived, he attempted to challenge Ichigo, but was interrupted by Ben. Grimmjow threatened Ben, but the latter was unintimidated and proudly revealed that he had defeated Aizen already, which was confirmed when Yoruichi Shihoin brought forth Aizen's corpse, much to Grimmjow's amazement.
Initially unsure of what to do next, Grimmjow quickly got over his shock and tried to challenge Ichigo again, only to be threatened by the Gotei 13, but he wasn't intimidated. Ulquiorra told Grimmjow that the surviving Arrancar would be staying in the human world, effectively giving Grimmjow control over Hueco Mundo. Though clearly tempted by the offer, Grimmjow still demanded a fight, at which point Ben offered to fight him. Grimmjow agreed on the condition that he would be allowed to kill everyone else if he won, to which Ben agreed (ignoring the protests from the Gotei 13).
Grimmjow immediately unleashed his Resurreccion, while Ben chose to use Ultimate Echo Echo. Despite driving Ben into a corner a number of times and even using some of his strongest attacks, Grimmjow was overpowered when Ben used Sonic Doom to overwhelm his enhanced hearing, causing him to collapse. Unwilling to admit defeat, Grimmjow struggled to his feet, declaring that the fight wasn't over until someone was dead. Ben then offered him a deal: one fight every weekend. Grimmjow agreed and returned to Las Noches.
Ruling over Hueco MundoEdit
After returning to Las Noches, Grimmjow was confronted by Loly Aivirrne, who demanded to know what had become of Aizen. Either out of cruelty or because he had not been fully informed of the true circumstances behind Aizen's death (likely both), Grimmjow off-handedly stated that Ben had killed Aizen, much to Loly's horror; in reality, Aizen had been killed by Gin Ichimaru after Ben had stripped the rogue Shinigami of his powers using Alien X.
Grimmjow would come to Bellwood (Ben's hometown) every weekend for a fight, as per their deal. The first time occurred during a beach party that Ben and his friends were having, with Ben transforming into Jetray. The results of this battle are not shown, though Ben likely won. When the next weekend rolled around, Grimmjow once again came to Bellwood, but ended up fighting Ulquiorra instead because Ben was on a date with Harribel, much to his annoyance.
When Saturday rolled around again, Grimmjow told Loly and her partner Menoly Mallia where Ben lived simply to get them to stop annoying him, though he was also confident that Ben could deal with them. After Ben and the Tres Bestias drove the duo off, Grimmjow appeared, demanding his weekly fight. Unable to persuade him to wait any longer, Ben acquiesed to Grimmjow's demands and fought him, their battle ending in a stalemate. Despite there being no definite winner, Grimmjow returned to Las Noches anyway. Ben asked why Grimmjow did not wish to kill him, and Grimmjow explained that Ben had become "too much fun to kill" before leaving through a garganta.