Kugo Ginjo from Bleach was first featured during the Lost Substitute Shinigami arc as the main antagonist and later in the Thousand Years of Blood War arc. Ginjo is the leader of the Fullbringer group, Xcution. He was also known as the first Substitute Shinigami before Ichigo Kurosaki.
He is not an explicitly evil character, but his actions make him villainous. Ginjo was first seen interacting with Ichigo, who recently lost his powers, helping him acquire Fullbring. However, his ulterior motives were something else, landing him in a morally gray area.
Disclaimer: This article contains spoilers from the manga/anime and reflects the writer's opinions.
Kugo Ginjo's past narrative in the Bleach series

Kugo Ginjo was the very first Substitute Soul Reaper from the Soul Society before Ichigo from Bleach. He was also a Fullbringer upon inheriting its traces upon birth because a Hollow had attacked his parents, leaving remnants of his power in them. Upon being named the title, Ginjo received the substitute soul reaper badge just like Ichigo as a form of identification.
Jushiro Ukitake, the captain of Gotei 13's 13th Division, presented Ginjo with the badge. He also came in contact with a fellow young Fullbringer named Shukuro Tsukishima during that time. Upon learning about Tsukishima's loneliness, Ginjo insisted he follow Ginjo, which he agreed to. From that day onwards, Ginjo mentored Tsukishima and taught him to fight and use his Fullbring powers.
Ginjo discovered the badge's true nature: It was not just a form of identification but a tracking device. The badge could track the holder's movements and even control them to a certain extent. Moreover, as Ginjo discovered, the badge could also manipulate the holder's spiritual pressure.

Ginjo, upon becoming the Substitute Shinigami, was nothing more than a pawn in the plot orchestrated by the Tsunayashiro Clan. They wanted to acquire Soul King fragments from the Fullbringer corpses by using Ginjo. Tokinada Tsunayashiro placed surveillance on the badge to track Ginjo's Fullbringer associates.
The Tsunayashiro family then proceeded to orchestrate a massacre of the Fullbringers, after which a furious Ginjo retaliated by killing the Shinigami assassins. Believing that Ukitake had personally betrayed him, Ginjo went rogue.
Ginjo felt betrayed and shattered, as becoming a Shinigami was a joyous moment for him. He abandoned his post and started attacking other Shinigami to gather more power and strengthen his Fullbring. Eventually, he disappeared from the Soul Society, unbeknownst.
Kugo Ginjo makes an appearance in the Bleach series

Ginjo's first appearance in the Bleach anime is in episode 343, post-Gotei 13 Invading Army arc. He was the main antagonist from the Lost Substitute Shinigami arc. As the arc began, Kugo and Ichigo came face to face. Kugo enters Ikumi's shop and inquires about Isshin Kurosaki, Ichigo's father, and claims there are things about his family that Ichigo doesn't know yet.
This was all his ploy to gain Ichigo's trust. He follows it up by attacking Uryu, who is pursuing Tsukishima, and later attacks Tsukishima to gain Ichigo's trust. Ginjo, alongside his rallied group of Fullbringers, tells Ichigo that their true intention was to bring back his powers.
Later on, as the story progresses, Kugo Ginjo eventually betrays Ichigo. His entire ploy was to make Ichigo achieve his Fullbring, killing him and absorbing his power into himself later. This was all so that he could exact his revenge on the Soul Society that betrayed him. As members from the Soul Society arrive, Ichigo gets back his Shinigami powers and boosts them with Fullbring, slashing Ginjo and defeating him.
However, the narrative eventually redeems Ginjo's character. During the Thousand Years of Blood War arc, Ginjo, alongside Tsukishima, was brought back to the Soul Palace to aid Ichigo and repay their debt. Ginjo and Tsukishima side with Ichigo in his battle against Yhwach. Tsukishima then helps Orihime repair Ichigo's Bankai to repay his debt.
Final Thoughts

Despite being shown in the light of an antagonist, Kugo Ginjo had his reasons to act. His story also tells the fans about the dark side of the Soul Society. His character cannot entirely be called evil due to the presence of evidence of what made him do what he did.
With the ongoing Thousand Years of Blood War arc unfolding, Ginjo's contribution to the storyline has yet to be seen. Moreover, fans anticipate his redemption arc toward Ichigo as the story continues.
Also read:
- Bleach: Thousand-Year Blood War Part 4 confirmed with PV
- 10 most important characters in Bleach: Thousand Years Blood War Arc
- Will Espada and Xcution return in Bleach: Thousand-Year Blood War?