Bleach is the story of Ichigo Kurosaki, a teenage boy who has the power to see spirits, one day he encounters Rukia, a shinigami, after that his family is attacked by a hollow (an evil spirit), Rukia is hurt and in order to protect Ichigo and his family transfers his powers to Ichigo, who then becomes a substitute shinigami. The early part of the story deals with Ichigo defeating hollows in Rukia's place as his agent, and how Ichigo's friends (Orihime, Chad, Uryu) start gaining there own spiritual powers, eventually Soul society comes for Rukia who is taken prisoner due to a crime, Ichigo and friends go to rescue her from Soul society, this introduces the gotei 13 (the 13 squads composed of shinigami) including there vice-captains/lieutenants and captains which play important roles later on, the soul society arc is generally agreed as quite good and the best part in Bleach. After it follows The arrancar arc, which introduces the arrancards and vizards which are hollows with shinigami powers and shinigamis with hollow powers. It also introduces the concept of hybrids and trascendentals.
After the Arrancar arc Ichigo loses his powers in his fight with Aizen, but during The lost shinigami arc a new group called Xcution appears and helps Ichigo regain his powers.
Currently Bleach is in the Thousand-Year Blood War arc which presents the WandenReich, a group of quincies hiding in the shadows all this time trying to take down soul society and the Soul King.
The power of this verse is around mid tier in anime/manga. It easily enters the hypersonic+ to massively hypersonic ranges of speed, and sub-relativistic range with the god tiers of the verse. It has worlds filled with spiritual beings and the top tiers of the verse easily pass city level power some reaching even much higher than that and most relevant beings/characters being considerably durable. Also the hax of this verse is slightly above that of the other members of the HST (Naruto and OP) it has a few characters worth individual distinction with abilities that are extremely dangerous, noteworthy examples of this haxed characters would be Barragan and his "aging", Tsukishima and his ability to insert himself in an objects history, Aizen's Kyoka Suigetsu's perfect hypnosis, Head captain Yamamoto's 15,000,000 degree Zanka no Tachi, As Nodt's "instinctive" fear, Quilge Opie's abilities in general, Ichibei's and Yhwach's everything regarding how there abilities work pretty much, amongst many others.
The author apparently has a thing for massive structures as the Seireitei and Las Noches are both 200+ kilometers by character claims or the path to the Royal dimension which took Ichigo half a day to cross despite him easily being as fast as lightning. Due to this theres been a noteworthy boost in firepower as well as Kenpachi destroyed a multi kilometer meteor meant to at least destroy all of the Seireitei.
The peak of power in Bleach was during the "Deicide" mini-arc, in which Ichigo and Aizen trascend the plane of simple spiritual beings and go far above the scope of power of normal spiritual beings, however there are little feats for them since they lasted only a few chapters with this level of power, so there is mostly only scaling to adress the true power they reached.
Recently the verse has gotten a boost since its in the climax of its final arc, showing planet+ and cross-dimensional AoE for its hax and speeds that are around 4 digits. The series is currently nearing its end and competing with Naruto for strongest of the HST.
The Soul King
Ichigo Kurosaki (Final Tensa Zangetsu)
"Ōorigami" Senjumaru Shutara
"Tōshin" Ohetsu Nimaiya
"Kokuō" Kirio Hikifune
"Sentōki" Tenjiro Kirinji
Gerard Valkyrie "The Miracle"
Lille Barro "The X-Axis"
Sōsuke Aizen (shinigami)
Calcs, feats, etc.
A compendium of noteworthy Bleach feats (up to early Thousand-Year Blood War arc): https://www.facebook.com/groups/454033638040208/permalink/465789936864578/