Most of Bleach's characters, especially those playing positive roles, remain alive for a large part of the narrative. Negative characters —Hollows, Quincy, Fullbringers— are killed off now and then, but even these cases are pretty infrequent. What's important is that the protagonist, Ichigo, like his shonen Big 3 compatriots Luffy and Naruto, abstains from bloodying his hands for the most part.
Most of the deaths that occur in Bleach are caused by the Shinigami, at least until the manga's Thousand-Year Blood War arc, in which dozens of characters start dropping like flies. How do the other arcs in the story compare with the final one, though?
7 The Soul Society Arc (0 deaths) — There Are A Few Death-Related Plot Twists Though
Nobody dies in The Soul Society arc, but there isn't any clarity until the final chapters/episodes. Aizen is apparently murdered and crucified against a Seireitei building, but this obviously turns out to be a sham generated by Kyoka Suigetsu. Rukia is seconds away from having her literal soul incinerated when Ichigo rescues her.
Finally, Aizen seemingly kills his Vice-Captain and biggest admirer, Momo Hinamori, and even bids her farewell while she lies in a pool of her own blood. She survives his attack (and another attempt in The Fake Karakura Town arc), though.
6 The Lost Substitute Shinigami Arc (3 deaths) — All Of Them Fullbringers
The Lost Substitute Shinigami arc is the least favorite among fans, partly because of its tiringly unrelated storyline, but mainly because the anime got canceled right after this arc (leaving way too many loose threads hanging). Ichigo tries to regain some semblance of power, and falls for Kugo Ginjo's allure —the ex-Substitute Shinigami easily tricks his successor into handing over his Fullbring, leaving Ichigo utterly distraught.
Thankfully, Rukia stabs him with one of Urahara's inventions, restoring the hero's reiatsu and then some. In the series of battles that proceed, Shukuro Tsukishima is killed by Byakuya, Kenpachi destroys Giriko Kutsuzawa, and Ichigo makes his first intentional kill: Kugo.
5 Agent Of The Shinigami Arc (5+ deaths) — Everyone Who Dies Here Is A Hollow
The first arc of Bleach, the Agent of the Shinigami, shows Ichigo gradually getting used to his new role as the Substitute Shinigami for Karakura Town. Over the course of several episodes/chapters, the hero and the audience are simultaneously introduced to the concept of Hollows, Soul Society, Shinigami, and so on. Ichigo and co. go on to "purify" Hollows like Fishbone D, Shrieker, Bulbous G, Hexapodus, and The Demi-Hollow.
In addition, there are a few humans who die of non-paranormal causes during this arc, turning into Plus Ghosts. Although Ichigo hones his Zanpakuto abilities with every Hollow killed, he doesn't quite have access to Zangetsu at this point, and therefore knows nothing about Getsuga Tensho. This is why he loses miserably to Captain Byakuya Kuchiki at the end, despite having nearly defeated Vice-Captain Abarai Renji.
4 Hueco Mundo Arc (6+ deaths) — A Few Espada Are Killed
The Hueco Mundo Arc doesn't have many deaths, but those that do perish are among the more powerful characters in the story. The Espada Aaroniero is crushed by Rukia, despite taking on Kaien Shiba's form to taunt and distract her, while Byakuya Kuchiki follows his sister's battle with Zommari Rureaux, obviously coming out victorious.
Two fights that stand out here are Nnoitra vs. Kenpachi (after the former consequently "defeats" Ichigo and Neliel), in which the 5th Espada is inevitably massacred. Mayuri Kurotsuchi takes on the Espada scientist Szayelaporro Granz, finally subjecting his opponent/victim to one of his patent chemical curses of eternal pain.
3 Arrancar Arc (7+ deaths) — Minor Arrancar Deaths
A large fraction of kills in the Arrancar Arc consists of lower level Arrancar like Nakeem Grindina, Yylfordt Granz, Luppi Antenor, Aldegor, Edrad Liones, and Shawlong Koufang.
This doesn't mean that there aren't enough battles to satisfy audiences, though, like Grimmjow vs Ichigo and Uryu Ishida's long awaited showdown with his father, Ryuken. In fact, Ichigo's dad is revealed to be a Shinigami when he defeats and bifurcates Grand Fisher's latest Arrancar form, courtesy of Aizen and the Hogyoku.
2 Fake Karakura Town Arc (13+ deaths) — Most Of The Arrancar Perish
The Fake Karakura Town arc begins when Aizen and his three main Espada —Coyote Starrk, Baraggan Louisenbairn, and Tier Halibel enter the real world, together with their Fracción. Starrk is forced to include his other half, Lilynette Gingerbuck, in the battle against the overwhelming Shunsui Kyoraku, but this plan fails miserably.
Baraggan arrogantly denies his defeat until the very end even when Suì-Fēng and Hachigen's ultimate team-up brings him down. Aizen cuts Harribel down, but she survives and is later seen in Hueco Mundo, a fortune shared by her minions, the Tres Bestias. Ulquiorra falls to Vasto Lorde Ichigo around the same time in Las Noches, and the final Espada obstruction, Wonderweiss Margela, is shattered by an unarmed attack from the Captain-Commander.
1 The Thousand-Year Blood War Arc (35+ deaths) — Characters Are Killed Off Left & Right
The final saga of Bleach, culminating in 2016, is told through the Thousand-Year Blood War arc, starting with a Quincy attack on Soul Society that leaves one Shinigami (Sasakibe) dead in the first few chapters. He is followed by several more, including Yamamoto Genryusai, Unohana Retsu, Nemu Kurotsuchi, and Jushiro Ukitake. In any case, maybe all their deaths weren't in vain after all, because Ichigo finally manages to end the bad guy, Yhwach, for all time.
In addition, the Sternritters Liltotto, Najahkoop, Waccabrada, Haschwalth, Giselle, Loyd and Royd Lloyd, Gremmy, Bambietta, Quilge, Äs Nödt, Robert Accutrone, Mask de Masculine, Gerard Valkyrie, and pretty much everyone on Team Vandenreich meets their end. Sadly, the Soul King, meant to corral the various forces holding the dimensions together, is killed due to Yhwach's actions. The canonical novel set after the end of the manga explains that Yhwach has been made the new Soul King, although it's not known whether he's alive, dead, or something in between.