The 'Zanpakuto' or 'Soul Slayer' is the main weapon that a Soul Reaper uses in battle. Soul Reapers train and, after a while, they are given a Zanpakuto. As you train and get to know your blade, it becomes stronger.
Eventually, after learning the name of your blade, it transforms into a stronger version of itself known as Shikai. If a Soul Reaper trains long enough, or employs Urahara's traning methods, they can gain access to the ultimate form of a Zanpakuto, the Bankai.
Also known as the Sacred Spear, Shinso was wielded by Gin Ichimaru. In its Shikai form, this blade can extend at a rapid speed, with powerful force. It can stretch as far as 100 hundred times its original length.
Gin used this ability to beat down Ichigo multiple times. In its Bankai form, the blades speed and destructive power greatly increases. It is believed that, in this form, the blade can stretch up to 13 km and move 500 times the speed of sound.
9 ASHISOGI JIZO
This blade is used by the Soul Reaper, Mayuri Kurotsuchi, captain of the 12th division in the Gotei 13. This blade grants a poison-like ability to its user. Any person who comes in contact with the blade will be paralyzed.
Oddly enough, despite this paralysis, victims can still feel pain. When Mayuri uses his Bankai, his sword becomes a gigantic baby-like, poison demon. In its Bankai form, this poison is so deadly that once it comes in contact with you, your body immediately starts breaking down. This deadly poison also spreads rapidly over a large area.
Kisuke Urahara is the former captain of the 12th division and one of Soul Societies' greatest ever scientists. His experiments has pushed his Zanpakuto beyond its limits, much like Mayuri.
In its Shikai form, Benihime produces this crimson aura that Urahara can use to his will. Benihime's Bankai allows it to restructure anything it cuts. This can be used for a variety of purposes, such as stitching things back together so it can heal. Offensively, it can also rip things apart, dealing incredible amounts of damage.
Much like its user, Nozarashi is a pretty straight forward and simple blade to understand. It grants Kenpachi even more destructive potential than he already possesses.
When released into its Shikai state, Nozarashi becomes massive and is powerful enough to cut through space. Kenpachi's Bankai turns him into a demon-like creature, who is far more powerful and much quicker. His skin also turns red and he acts on pure instinct and bloodlust.
The wielder of Senbonzakura is the 6th division captain of the Gotei 13 and 28th head of the Kuchiki Clan, Byakuya Kuchiki. This blade has the ability to seperate itself into a thousand tiny blades, that all appear to be like sakura blossoms.
These blades are too small to be seen with the naked eye, but appear pink when light refracts on them. Byakuya can then control all these blades however he wishes. In its more advanced Bankai form, the number of blades greatly increse allowing for more devastating techniques.
This is Ichigo's Zanpakuto and is pretty simple. Much like Kenpachi's, this blade greatly enhances Ichigo's speed and power. When attacking, Zangetsu absorbs his spiritual energy, condenses it and then launches this condensed energy from its blade.
Ichigo mainly uses this for his famous Getsuga Tensho attack. Tensa Zangetsu, his Bankai takes this to another level. He becomes faster, stronger and more durable. A Getsuga Tensho with Tensa Zangetsu was almost enough to kill Yhwach, the strongest character in Bleach.
"Counter Stroke" is Shinji Hirako's sword. Shinji is a former member of the Visored and current captain of the 5th division in the Gotei 13. When Shinji spins his sword, a pink mist comes out of it and anybody who smells it gets hit with his sword's ability, "Upside Down World".
This ability flips the victim's perception. Left becomes right, up becomes down and backward becomes forwards. Shinji can even invert his words causing his opponents to become even more confused and disoriented. This ability also inverts the senses of the victims as well. That is, if they were to get cut on their left leg, they would think it was their right leg that received the damage.
3 KATEN KYOKOTSU
Katen Kyokotsu is wielded by the current Captain Commander of the Gotei 13, Shunsui Kyoraku. Shunsui also holds the distinction of being the captain of the first division, and the former captain of the 8th division. This sword's special ability can force anyone who steps into the range of Shunsui's spiritual pressure into 'playing games'.
Shunsui decides the special rules of these games and played a wide range of them during his fight with Coyote Stark. His Bankai takes his opponent into a dark and dreary setting, and damages the opponent in four seperate "Acts".
2 KYOKA SUIGETSU
Aizen is a former inmate of the prison Muken, having been imprisoned for waging war against the Soul Society in an attempt to become 'God'. Of course, Aizen is also a former captain and lieutenant of the 5th division of the Gotei 13.
Kyoka Suigetsu's special ability, "Perfect Hypnosis", forces any person who looks at the blade to fall under Aizen's hypnosis. This hypnosis is absolutely inescapable once you fall under its effects. This ability was the foundation of Aizen's plan to become God and he almost succeded.
1 RYUJIN JAKKA
The extremely devastating flame Zanpakuto of the former Captain Commander of the Gotei 13, Genryusai Yamamoto. When Yamamoto releases his blade with the command, "turn all creation to ash", flame bursts forth from his sword and anything it comes in contact with, gets burned to ash. Ryujin Jakka's flame burns intensely and engulfs Yamamoto's surroundings, burning anything he wishes.
Zanka no Tachi, its Bankai form, condenses all his flames into his blade and anything Yamamoto cuts, gets burned out of existence; nothing remains, not even ash. The flames of Zanka no Tachi are so intense that it even dries up the moisture of anything that comes into contact with Yamamoto's spiritual pressure.