New Headcanon Book

Squad 55 (Bleach, OC)

The Fox of the Reflected waterdrop - Yumihime Zonda 
Zanpakuto: Himiko (Somehow a floating mirror styled zanpakuto that isn't a katana, though the mirror also floats, it housed himiko, the shaman queen of yamataikoku, Resembling a humanoid shaman queen wearing a mirror like mask, upon unmasking however, she's a beautiful woman, she has long hair which reaches half of her back, wears a kimono and slippers, and she has D size buxom.)
Yumihime appearance is that she is 5"3 in height, pale skin, has white hair and her eyes are blue by color, her age is 21 years old and she wears the soul reaper lieutenant Attire with number 55 hanging on her shoulder band. Her white hair is long and it reaches her shoulders and she has DD size buxom. which himiko, her zanpakuto spirit feels a bit surprised and praises her master.
Shikai: Mirror Reflecting water drop of mae (A shikai taking form of a elegant and imperial mirror, the shikai special ability allows her to draw out her energy of reiatsu and transforms it into powerful kido spells, notably her favorite is mirror reflecting stone and Elemental storm, she gains fox ears and a single fox tail)
Release command: Reflect
Bankai: Tamamo no Kanzeon Reflecting Mirror (Similar to her zanpakuto and shikai form, the mirror is now divine and elegant by form showing the zodiac signs hanging on the left and right *six on the left and right*, her bankai special ability allows her to recognize her enemies via precognition and examining them, also now she has four tails and she gains red markings
Beyond Bankai: Kouzeon Tamamo no Mae or Tamamo no Kouzeon (Upon achieving her beyond bankai, she now fuses with himiko and gains a divine robe, three mirrors floating around her with first mirror is the present, second is the past and third is the future, her zanpakuto mirror is now a giant mirror, now her tails are nine and the markings are now seen, and her eyes turns royal red, her beyond bankai special ability allows her to perform ninefold blessings of himiko

Vermin of the metamorphosis - Gregor/Goren Mendel (Goren mendel appearance is that he is 6"1 in height, he wears his soul reaper lieutenant attire but he likes being shirtless to show his twelfth pack muscles, black hair and is long though tied to ponytail, gray eyes, and he is tanned skin, his appearance changes, upon shikai, he gains a insect like appearance as it continues to evolve, upon bankai,
Zanpakuto: Metamorphosis (Somehow a bamboo staff zanpakuto with tiny insects crawling around, its true name is tithonus, the greek god of insects, the god in question seems to be a giant grasshopper)
Shikai: Vermin of Emergence (A bo staff shikai with bugs crawling around, shikai special ability seems to call insects to attack, shikai insects are locusts, flies, and gnats)
Release command: Emerge
Bankai: Tithonus insect lord (It combines with him, giving him a rider like appearance, notably because of tithonus, he becomes a grasshopper rider, he also has a red scarf and the coloration seems to be forest green and black with lens being bright red, bankai insects are all grasshoppers)
Beyond Bankai: Legerdemain Tithonus (Much like kamen riders, there is a super form at hand, and Goren is using it, upon awakening his beyond bankai, he exchanges his grasshopper design for a more powerful approach, being rhinoceros beetles and his armor weights him, upon breaking it, he becomes faster and stronger, also it gives him the ability to "Slow Time" because he has faster reiatsu regen, his beyond bankai ability? He's capable of using other zanpakuto's by just borrowing them)

Reflecting Moon Princess - Luna Tsukuyomi (She is the same height as himiko, tanned skin, blue moon colored hair and it's a hime-cut and her hair is long till neck length, she has B size cups, wears the soul reaper lieutenant uniform though hers is kimono like, and she has black eyes.)
Zanpakuto: Eclipse Moon (Her zanpakuto is a chained chakram like weapon, her spirit is tsukuyomi himself, representing as a robed mirror humanoid. her appearance changes, in shikai she has moon yellow and moon blue hightlights on her hair and on bankai clear blue eyes)
Shikai: Moonless Eclipse (Her shikai weapon form seems to be dual chakrams with the blades being crescent by shape, her shikai special ability allows her to create illusions by raising her chakrams)
Release command: Weep
Bankai: Twin morality of black and white Tsukuyomi (Now she wields chakram fans with her bankai special ability being able to send the feathers as projectile)
Beyond bankai: Flowery Moon of tsukuyomi (Her outfit seems to be inspired from kaguya hime from tale of the bamboo cutter and her hair color is now dominant moon blue with moon yellow as the highlights, she also has rabbit ears, now she carries a giant chakram like weapon instead of her dual chakrams, her beyond bankai ability now allows her to perform getsuga tenshou - Tsukuyomi)

Crossing the fate of hell - Granz Ciel (Granz Ciel is 5"10 in height, wears the soul reaper lieutenant uniform, dark brown skinned, blue eyes and his hair is short but shaggy styled - color is black, though he has multitudes of scars surrounding his body including his upper pecs and lower abs, he is muscular btw and eight packed, his zanpakuto spirit is no other than hi-no-kagutsuchi or kagut-suchi. resembling a giant fire god with chains surrounding it's body parts where izanagi once cuts it. his appearance changes, first in his shikai, a skull slowly forms behind his back and upon bankai, the skull is now fully formed and it was a human skull and his head is now replaced with a flaming skull)
Shikai: Woven by fate of the hitodama (A Single-edged chained katana with fate weaving in the chains, shikai special ability seems to Redirect his damage to his enemies)
bankai: Homusubi Chained Fire (Upon bankai, now it's a odachi with flames surrounding the blade and the guard now resembling a lotus, the bankai special ability allows him to fully redirect damage back and gains flames of vengeance)
Release command: Chain
Beyond bankai: Homusubi Sinners of Flame (Soon his flames now become infernal blue and red as his outfit now resembles a warlord and a ronin at the same time, his zanpakuto looks more marred or broken down as a result of fighting, the form it takes shape is a nodachi as opposing to him using a odachi in bankai, bankai special ability allows him to perform boundary of death (Fourfold of death / Shi-bai no Shi)

The Turnover the dimensional Repetition - Regad Virchow  (Somehow a orca shinigami who came into squad 7, despite his "Well" not human appearance, regad virchow is a black and white killer orca who wears his specialized soul reaper uniform, notably being a bit more marine-like or a islander and he is 7"4 by height and hypermuscular)
Zanpakuto: Mandala (Somehow a regular spear zanpakuto  with a rope surrounding the blade hilt, It's zanpakuto spirit seems to be called amenominakanushi or minakanushi. a monk of fate and destiny who is a heavy robed monk with mandala beads)
Shikai: Realm Mandala - Triangular (Spear with the blade being a naginata type, shikai special ability allows him to set up realms, which are boundaries)
Release command: Immortalized
Bankai: Mandala of the thousand realms of samsara (Now he carries four spears, each representing the four realms of the mandala *Realm of Life, Realm of Death, Realm of reincarnation, and Realm of Fate. Bankai special ability uses the four realms arts and reiatsu)
Beyond bankai: Interwoven wheel of samsara (Now he dual wields his spears and he's wearing a monk robe with him wearing a bead necklace around his neck and a monk hat. The beyond bankai special ability is inflicting his enemies with all different status effects)

The Treasure hunter - Daiki Wu (A Silver-snowed fox with cyan eyes and he is hypermuscular by form, he is 7"6 by height, wears the captain soul reaper outfit *His however is designed to be more akin to winter clothing that humans wears* and wears black gloves, due to his fox form, his ears are similar to regular foxes but his tail is big and unlike yumihime, he doesn't grow many tails)
Zanpakuto: Obariyon (He is wielding a katana with a golden guard and the blade seems curved by shape, the zanpakuto spirit is obayiron, a mischievous imp youkai who usually hangs around the zanpakuto a little longer, it's true form is a japanese coin hanging on the handle via rope)
Shikai: Golden treasure obayiron (Somehow a Wakizashi with a gold blade, it's shikai ability seems to influence "luck")
Release command: Snipe
Bankai: Webisu Golden Fortune (if  Turning a wakizashi into a bayonet sniper rifle wasn't that enough, daiki bankai allows him to fire at the enemy at long range and stab them at close range, his bankai special ability allows him to utilize coins as "Ricochet" targets for the bullets to hit and exploits luck in his favor)
Beyond bankai: DiEnd Treasure hunter (Of course, a kamen reference, though unlike goren who becomes a rider-esque upon bankai, Daiki Wu became Kamen Rider DiEnd Thanks to obariyon buying a Actual DiEnd Driver, soon becoming kamen rider DiEnd with soul reaper on the chest. also he has access to supporting riders powers and can become complete 25 (Vulcan and Valkyrie, Blades and Espada, Evil/Live and Jeanne, Buffa, tycoon and Na-Go which can be changed), and Valvarad)