There was a time when Bleach was part of the shonen Big Three, and it has recently seen a resurgence in popularity thanks to the first installment of the highly anticipated Thousand-Year Blood War Arc. In terms of quality, Bleach's story is just above mediocre, but fans love the series because of the battles and power systems. It also helps that Bleach has a variety of very well-designed characters.
Most of these characters are high-ranking Soul Reapers or Hollows who appear in multiple arcs, but each arc, whether it was filler or canon, introduced a number of new characters. It is true that certain Bleach characters only appear in a single arc, but some of them still managed to stand out because of their personalities and skills.
8 Ichibē Hyōsube (Thousand-Year Blood War Arc)
The Thousand-Year Blood War Arc has been a resounding success, and the eighth episode finally introduced the Zero Division, which is led by Ichibē Hyōsube. This monk is responsible for naming everything within the Soul Society, and the ink produced by his Zanpakuto is one of Bleach's most overpowered abilities.
At first glance, Ichibē looks like a loud and upbeat individual, which he is, but he is also an authoritative figure who never loses focus of his objective. In battle, he becomes ruthless, and he will patronize his opponents in a kind manner. He will smile throughout the battle, and when he decides to kill someone, he gets much happier.
7 Koga (Zanpakutō: The Alternate Tale Arc)
Zanpakutō: The Alternate Tale Arc introduced Koga, a never-before-seen member of the Kuchiki Clan. He married into the family, and he served as the 3rd Seat of Squad 6 when Ginrei Kuchiki served as Captain. His Zanpakuto had the power to take control of other Zanpakuto and turn them against their masters.
Koga was framed for murder, and after being sentenced, he was freed from prison by his Zanpakuto's spirit. He then went on a killing spree and grew more and more unstable until he began abusing his Zanpakuto. He was eventually sealed, and when he was finally released, he faced Byakuya in an epic sword fight.
6 Nozomi Kujō (Gotei 13 Invading Army Arc)
The Gotei 13 Invading Army Arc took place shortly after Aizen's defeat, and it showed how Ichigo was gradually losing his Soul Reaper powers. During the arc, many of the Captains and Lieutenants were replaced by special mod-soul duplicates.
Nozomi Kujō was the first Mod-Soul created by Project Spearhead, and she was hunted by Kagerōza Inaba, her other half. She may not be one of the strongest female characters in Bleach, but she is very independent, and she becomes far less defensive as she gets closer to Ichigo and Kon. She has a Zanpakuto which absorbs all forms of spirit energy before releasing it as an attack.
5 Hyōrinmaru (Zanpakutō: The Alternate Tale Arc)
Toshiro Hitsugaya is one of the strongest Gotei 13 Captains because he wields Hyōrinmaru, the strongest ice-type Zanpakuto. During the Zanpakuto Alternate Tale Arc, most of the high-ranking Soul Reapers were forced to fight the physical spirits of their Zanpakuto, and Toshiro had to deal with Hyōrinmaru.
Unlike the other spirits, Hyōrinmaru had no memory of his master, and he refused to believe that a child would be able to wield him. He spends a great deal of time searching for his master, so he can find a place where he truly belongs, and this leads to an emotional fight with Toshiro.
4 Ashido Kanō (Hueco Mundo Arc)
When Ichigo and his friends ventured into Hueco Mundo to save Orihime, Rukia got separated from the group and ended up in the Forest of Menos, where normal Hollows go to hide from the Arrancar. While there, she met Ashido Kanō, a Soul Reaper who had been living in the Forest for centuries.
He and his team followed a group of Hollows into Hueco Mundo, and he now lives with the mental scars of his teammates' deaths. He decided to stay in the Forest to kill as many Hollows as possible in order to protect the Human World. He saves Rukia when the two first meet, and he helps her to escape the Forest.
3 Shūsuke Amagai (The New Captain Shūsuke Amagai Arc)
A number of Captain positions opened up when Aizen, Tousen, and Gin left the Soul Society, and Shūsuke Amagai was chosen to fill one of those positions. He rose through the ranks of the Patrol Corps and eventually succeeded Gin as the Captain of Squad 3, but he was actually a villain who wished to kill Captain-Commander Yamamoto.
His quest for vengeance began once his father died, as he believed that Yamamoto had him killed in order to hide the existence of the Bakkōtō weapons. He confronts the Captain-Commander and nullifies his Zanpakuto, which meant that Yamamoto could not use his strongest abilities.
2 Muramasa (Zanpakutō: The Alternate Tale Arc)
Koga only became a target because his Zanpakuto, which was named Muramasa, possessed a dangerous ability. He was the mastermind behind the Zanpakuto rebellion, and he orchestrated the entire thing in order to free Koga from his seal.
Muramasa put his own life at risk to release Koga by absorbing Hollows, and he did this despite the fact that the latter abused him before getting sealed away. He just wanted Koga to appreciate him, which is why it was heartbreaking to see Koga cast him aside as soon as he was freed.
1 Jin Kariya (Bount Arc)
Jin Kariya was the leader of the Bounts, a group of artificially-created beings that fed on souls. Each Bount had a Doll that acted like a Zanpakuto, but Kin merged with his when he was very young, and it gave him the ability to manipulate air.
The Bounts' very existence threatened the balance of souls and Central 46 ordered them all to be killed. Jin and a few others survived, and his goal was to become powerful enough to invade the Soul Society and destroy the Seireitei. Jin may have been a filler character, but he provided Ichigo with one of his best fights.