Starting at the top left to right! (Descriptions are usually updated by Neo Ultra Mike and slightly edited by RockmanDash)
Zangetsu: Zangetsu is Ichigo's sword spirit and he has helped Ichigo train back in the "The Substitute Arc" and the "Soul Society Arc" in order to teach him the Getsuga Tensho and help achieve his bankai form. We haven't seen Zangetsu since the Bount arc and he didn't appear with Hollow Ichigo in the Arrancar arc. He joined Muramasa for awhile and helped him reach into Ichigo and pull out Hollow Ichigo, the other power source of Ichigo Zangetsu would normally be bonded to if Murmasa wasn't pulling his tricks. Ichigo beat him though and is now back to normal with Ichigo knowing Muramasa brainwashed the Zanpakutos with his powers and can't be taken by him again.
Senbonzakura: Byakuya's Sword Spirit; who takes the form of a masked samurai in full-body armor. He holds just as much pride as his previous master and he took it upon himself to make Byakuya somehow disappear with his "Thousand blades" technique. Now it can be revealed though: after that attack Byakuya fought him and got Senbonzakura back under his control but Byakuya decided to make it seem like his sword was still brainwashed and then later join Muramasa himself. So the two's various battles throughout this arc were really a front for this big fight: killing Koga. And though Byakuya had a disadvantage power and techinque wish with Koga, having his sword spirit with him allowed him to get an upper hand as the two working together is better then Koga working alone... wait wasn't that the point of Ichigo's first fight with Kenpachi? Jeez even the so called good filler fights always feel like rips on other battles we've seen before. And now the two spearheaded destorying all the other menos so they can kill more random menos around before returning to Byakuya's sword. Except he didn't for some reason and in order to stop the sword fiends he agreed with Sode No Shirayuki to throw a party and wound up getting drunk.
Suzumebachi: Soi Fong's Zanpakuto spirit who is the size of a bee and has a stinger for an arm. Unlike her master, she has no interest in Yoruichi and thinks Soi Fon's clothes are the worst fashion statement ever. She has just stung Soi Fong once and.....honestly she could probably take out all of the other soul reapers if she had the brain to think about it.Even though she had the complete advantage to take out Soi Fon, she was still easily defeated by Soi Fon's abilities that she should have already been aware of, and was now unbrainwashed and is working with her master.
Kazeshini: Hisagi's Zanpakuto spirit who takes the form of a red demon like figure who loves to fight. He seems to love the phrase "Kill and Slaughter!!" His blades were revealed awhile back and now he's engaged in a battle with Hisagi. Wanting to show the true nature of his weapon is taking lifes, like his former partner, who escaped thanks to Kira's help which annoyed the inner thrill to kill everyone swords. He has recently suffered defeat from Kira and now has been tied up, and was able to escape I suppose after Kenpachi's rampage and came back to Muramasa who gave him a chance to act on his instincts once more. Which meant to fight Ichigo and get taken out for good with a bankai Getsuga Tensho. Ichigo feels bad for breaking him, though once again he's never really met Hisagi so how would he know what his Zanpakuto looks like anyway? I guess like everyone else he's been brought back though he isn't around and is still in Soul Society.
Haienko: A cat spirit with a large booty who seems to enjoy talking about how beautiful she is. She's Rangiku Matsumoto's Zanpkato spirit and has been described by her former owner as rude, selfish, lazy and whiny. Which I'm sure is NOTHING at all like Miss Matsumoto. She not only has a massive crush on Hynoimaru but seems to constantly get into arguments with Tobiume who she seems to hate for being uppity and flat chested. And also calls her former owner old, even though she dosen't look a day over 30, despite probably being twice that actual age. She was recently tied up together with Tobiume after being outsmarted by Rangiku and Hinamori. For reasons I can't fathom both were caged instead of beaten to the point of going back into the sword and thanks to Byakuya are now on the loose again. After providing a distraction for Ashogi Jizo to... do something, now she and Tobiume are attacking Yourochi. And kind of obvious Yourochi can just curb stomp then but at least let's hope THIS is a battle they don't escape form at least. Well they did escape from before as Yourochi left them to take care of other things but now they escaped and are fighting her again. Afterwards she returns to normal with the rest of the Zanpakuto spirits thanks to Mayuri. During the Sword Beast Arc, she was seen goofying around with Matsumoto and Orihime in Karakura Town; this led to her later being saved by Ichigo from a Sword Beast.
Tobiume: Momo Hinamori's sword spirit. A young maiden who wears traditional Japanese clothing and holds two bells with a dull voice who likes throwing fireballs around. She also fancies Hynomiaru and also argues constantly with Haienko, hating her for being crude and skanish. Also really dislikes her old master for trying to think the best of eveyrone and being naieve. You know like a lot of people did after seeing she still might of been mind screwed by Aizen. She was recently tied up together with Haienko after being outsmarted by Hinamori and Rangiku. But are now back on the loose again thanks to Byakuya even though you'd think their arc would be over but... guess someone likes keeping them around. They were involved with the Ashogi Jizo attack went to the cave to bicker some more and are now fighting Yourochi. Who I hope decides to take them out for good (her second time fighting them) since their constant appearences are really getting grating. Has now been unbrainwashed and is working with Haienko against the Menos hoard.
Sode no Shirayuki: Rukia's sword spirit who takes the form of a beautiful white maiden. She recently just attacked Rukia and seems to have the total interest of killing her. It's revealed she wants to be free to do whatever she wants and after a long fight with Rukia was actually severly damaged by her to the point and seeing how far Rukia would go so she wouldn't hurt innocents actually made her start caring some more about what happened to her master it seems.She was recently destroyed by Byakuya, who took her down for the sole purpose of proving his loyalty to Muramasa. Her sword remains were handed over to Rukia who was shocked by these turn of events. But is Sode gone for good? No she was unbrainwashed and is now helping Ruika, the other Zanpakuto and soul reapers fight the menos. It is then revealed in "The Beast Sword Arc" that she was revived with an experiment that Mayuri was performing in a tube. She is currently now helping out Rukia track down any rampaging Sword Beasts and...suggesting absurd ideas like freezing the entire Soul Society or..having a party.
Gonryomaru: A man dressed up as a ronin traveler. Who uses lightning abilities against his opponents. ..Wait.....lightning? Somebody actually has a original power that hasn't been shown yet? Yes that's right it's the sword spriit of the Chojiro Sasiukabe aka the lieuntant of squad one. Who is annoyed at him not being recongnized due to well how little of an impression his former master made. Since yeah his former master dosen't even seem to be in this arc and last I checked the only fight we've ever seen him in had him defeated in one blow. Yeah that's right someone in this series fails harder then Renji if you want to believe that. And so does this guy, needing Tenken to lift him away fom a pile of rocks. Why did this guy think he could take on a captain again? Well turns out he couldn't as he was cut up by Kenpachi offscreen since he wanted to take on a real challenge; let's face it, this guy and Sasiukbe are kind of a joke..
Minazuki: A mysterious spirit masked in a green cloak seen with some other spirits attacking Yamamoto and with all the other old captain level Zanpakto, locked him away in some sort of fire dome for most of the arc. Now that it's revealed who the other pair of Zanpakutos is I can tell you she's Unohana's zanpakto. Will we see what that can do besides transport people around and heal them? Maybe as she was seen letting Ichigo chase after her but for some reason I doubt we'll actually see what she's capable of.She was recently burned too death by Ryujin Jakka after learning that Muramasa has no more interest in helping the Zanpakutos. And was probably brought back to... just float around some more since that's all she ever does in this arc.
Zabimaru: A Woman with Monkey fur around her body and a kid with a snake tail who are attached to each other by a collar. They are the Zanpakto of Renji Abarai. Originally just a monkey and snake they're true forms are quite different (perhaps thanks to Renji possibly altering his Zanpakto if that one Shinigami's Cup is to be believed). And though they argue and bicker a lot with one another, they hate Renji even more for being so pathetic and plan on crushing the show's ultimate soul reaper Jobber. They were later defeated by Renji's spirit to never give up and they came to their senses and realized they were being controlled by Muramasa, though they still seem to be able to pop back into sword spirits whenever they want. They lost against Senbonzakura but are now going to help Renji fight Byakuya and... failed offscreen and are now just laying down defeated. Way to epically fail yet again something related to Renji. They came back with Renji though to fight the Menos while Ichigo was stuck in the dome with Muramasa. During the Sword Beast Arc, Monkey and Snake decide to help out Renji chase Sword Beast into Karakura Town. However, this backfires when Snake decides to run away and seek his own freedom after being tired of his chain with Monkey. Snake eventually learns that his partnership with Monkey and Renji was a great bond thanks to Ichigo's sisters knocking sense into him; he later reunites with his partners and the Sword Beast they hunted down is later defeated.
Ashisogi Jizo: A golden baby with wings? Honestly, only some major freaky character would even dare have such a spirit! That's why he's Mayuri Kurotsuchi's Zanpakto (since honestly the face of this guy gives that away). He's now fluttering in front of Isane and Iba for... some reason. He has recently interuppted Kenpachi's fight with Byakuya and...got blown up by Mayuri. ......I feel kind of bad for the little guy.. but guess he's back with the other Zanpakuto right?
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Sogyo no Kotowari :Two very curious looking twin children spirits dressed in blue also seen attacking Yamamoto, and then holding him for most of the arc and are now fighting their master. Yes these are the Zanpakto spirits of Joshiro Ukitake who seems to have to keep fighting children, though at least these kids having his sword powers should give him more of a fight then Lilyentte at least.They were recently burned too death by Ryujin Jakka after learning that Muramasa has no more interest in helping the Zanpakutos. And have probably been brought back by... I don't know magic or something. And now they spend time just running around and playing and don't really expect much else from them in this arc.
Tenken: A red man who has fire in his mouth and stands tall with tons of power.. The Zanpakuto of Sajin Komamura who just struck a powerful blow against his former master. He seems to partner up with Gonryomaru as the two of them are fighting against Soi Fon as they seem ot make a kind of unusual tag team, who had to drag his partner out of the rubble. And now the two are fighting Kenpachi. Hey remember when there was an offscreen battle between Komamura and Kenpachi in the Soul Society arc that we never got to really see? Think this will make up for their not even match in Soul Society? Well we at least see Kenpachi charge more at him so... that's something I... believe. But nevermind that as he's back with Komohamura fighting Menos... yeah way to still not show a climax of that kind of interesting battle guys. Very classy of you.
Hozukimaru: Ikakku's Zanpakuto Spirit. He resembles an oni with dark brown skin and long messy orange hair. Unlike Ikakku, he has no fear over using his bankai against his opponents which he used to hurt his former master before taking off. He then fought Ikkaku again and after using all of his power, Hozikmaru was defeated and fell along with his master. He was later unbrainwashed and helped out the rest of the Soul Society to defeat the rest of the Menos that were rampaging around Muramasa.
Ruri iro Kujaku:A blue haired man who wears bandages with feathers. If he looks familar it's because he's Yumikchika's sword spirit and seems to be about as vein and fashion concious as his former partner. What seperates him though is caring more about appearence, hates being called Fuji Kukaju and has no problem using his full power which is a lesson one can only hope is pased on to his arrogantly vein master. He is currently taking down Yumichika easily with his true ability. Or was until Yumichika managed to get out of the attack and trick his sword into releasting it again so he could grab and strike him from behind, defeating him and sealing him away before passing out. He was later seen helping out Yumichika take out the Menos that were surrounding Muramasa's dome.
Hynomiaru: A man with light blue hair with a giant X mark covering his face. He is Toshiuru Hitsuguya's zanpakto, though he had no idea of that first. He recently regained his memories after fighting Hitsugaya and now sees the child as his master again even though Hitsugya's hurt but hey at least he has his Zanpakuto on his side at least. And he came with Toshiru into the fire shield to create an opening for Ichigo to get out. Because yeah, what really helps take care of fire? Ice attacks..... yeah I don't get it either. Afterwards he was seen helping out the Soul Society defeat the surrounding Menos that were near Muramasa's dome. Later on in the "Sword Beast Arc", he attended Squad 10's "party" and helped Ichigo against a rampaging Sword Beast with Hitsugaya.
Wabisuke: Kira's extremely unhealthy looking Zanpakuto. Hes a skinny man with a giant weight who seems to love enjoying coming out of nowhere to ambush others with his weight ability. He beat Kira but made the mistake of attacking Zaraki and got taken out in one blow easily. Oh well he still is the smartest for not talking that much and trying to take people out from behind so points on that. He was later revived thanks to Mayuri's experiments and arrived to help the rest of the Soul Society defeat the rampaging Menos that were surrounding Muramasa's dome.
???: A...robot..? I....don't know...what this thing is! Maybe we'll find out in the Sword Beast arc..
Katen Kyokotsu Second Sword: A mysterious woman with purple hair(with a skull on it) and has her face masked up. She looks like she could join the Kakashi fan club and was one of the ones who was shown going against Yamamoto and keeping him detained. This silent ninja girl is the shadowy half of Shushi Kyroaku's zanpakto who if we learned anything from in the Starrk fight is the second blade Kyroaku dosen't use as much as his other one. She was later burned too death by Ryūjin Jakka after realizing Muramasa had no more interest in helping the other Zanpakutos. Mayuri then revives her and the rest of the important broken Zanpakuto Spirits and they all attend the battle against the Menos surrounding Muramasa's dome.
Katen Kyokotsu First Sword: A volptorous, large breasted woman with purple hair and has a whole crossbone skull decoration on it. The other part of Shushi's Zanpakuto, though is a lot more talkative and chatty then the shadowy ninja girl. This pirate woman seems to really be the one fighting her former master. As for why these two are seperated even though they're one sword? Because unlike Zabimaru or Sogyo no Kotawari, Katen Kyokotsu obviously has it's two parts more seperate and works more indepently off each other.She was recently burned too death by Ryūjin Jakka after realizing Muramasa had no more interest in helping the other Zanpakutos. She's later revealed to be revived and well again in "The Beast Sword Arc"; she was seen playing "games" with Shunsui and defeating him to the point where she got to draw on his face.
Gegetsuburi: Omaeda's Zanpakuto spirit. Just like his wielder he is obnoxious and holds more speed than what his looks tell you. Ichigo was able to easily take him out without much trouble due to Omaeda being knocked out and has been taken ot be researched on by Mayuri. He was later unbrainwashed and helped out Omaeda defeat the Menos surrounding Muramasa's dome. .........Please don't give this guy his own episode..
Muramasa: Now this guy's story can be revealed: he was once the Zanpakuto of Koga Kuchiki, who was the the third seat of Squad and married with a member of the Kuchiki family. Muramasa's ability was to turn Zanpakutos against their Masters and make Soul Reapers fight their sword spirits or themselves, which in the result made Koga extremely power. However, there was those who feared Koga and decided to frame him to the point of where they trcked him of killing his men and had him locked up. Muramasa freed his master, Koga, who decided to take his vengence against the Soul Society. Koga eventually went mad with power to the point where Yamamoto and Byakuya's Grandfather had no choice but to seal him away. This leads on to how Muramasa's current plan was to take the Zanpakuto of the 13 Court Guard squads and turn them all against each other, this would allow enough chaos to occur where he could even take information from Yamamoto about where Koga is sealed. Muramsa eventually succeeds in taking over Yamamoto's Sword Spirit, finds the information, and at last releases Koga who... promptly stabbed his Zanpakuto spirit; he stabbed Muramasa as an act out of "revenge" for not helping him before he got sealed away. However, Koga failed to realize that he lost the power to hear his own Zanpakuto due to his own rage and thus Muramasa had no idea he was in danger at the time of his sealing. After Koga was killed by Byakuya, Muramasa transformed himself into a Zanpakuto Arrancar(due to eating hollows in order to survive without master) and trapped himself through a dark dome, which accidentally sucks up Ichigo as well. Ichigo and Muramasa clashed fiercly and eventually Ichigo came up as the victor, due to realizing the secret behind Muramasa's control abilites. In the end, Muramasa eventually dies to his wounds and finds it ironic that the last voice that reached him was from Ichigo. Even though he's currently dead, his spirit lives on through the "Sword Beasts"; Zanpakuto who were cursed with Muramasa's mind controlled ability and had their wielders killed before turning back to normal.