Summary
WARNING: The following contains spoilers for the Thousand-Year Blood War arc.
During the pivotal Hueco Mundo Arc ofBleach, Ichigo Kurosaki fights Cuatro Espada, Ulquiorra Cifer for the safety of Orihime Inoue and the opportunity to finally escape the nightmarish castle. However, after the defeat and apparent death of Ichigo, he rises once again,donning a form only seen this one time. What fans have called “Vasto Lorde Ichigo” has remained one of the most iconic transformations for one of the most famous battles in Shōnen anime. But the true nature of this form, why and how it happened, remains a highly debated topic among viewers.

With the revival ofBleachthanks to the Thousand-Year Blood War anime, many anime fans who missed out on the original series finally gave it a chance to catch up to the new phenomenon. When binge-watching the Arrancar Arc, Ichigo’s seemingly unexplained transformation left new fans, albeit incredibly excited and amazed, also quite confused, as this monstrous appearance catches viewers off-guard.
The Origin of Ichigo’s Powers and Zanpakutou
As revealed during theEverything but the Rain and The Blade is Me mini-arc, the old man with the sunglasses in Ichigo’s inner world is not the real spirit of his Zanpakutou, Zangetsu, but instead, the manifestation of Yhwach, the Quincy King, as Ichigo’s dormant Quincy powers. The real Zangetsu has always been the antagonistic Hollow Ichigo. Hollow Ichigo, who will be referred to as Zangetsu from now on, is a unique creature, as Ichigo’s origin is unlike any other Soul Reaper.
Many years ago, the captain of the 10th Squad, Isshin Shiba, battled a special Hollow created bySosuke Aizennamed White. White was created by merging the souls of many Soul Reapers and then Hollowfy it, resulting in an extremely powerful Vasto Lorde-class Hollow with Soul Reaper reiatsu. When White infected Masaki Kurosaki with his Hollow reiatsu, Isshin’s Soul Reaper powers were used to save her life. This results in Ichigo, a perfect hybrid ofSoul Reaper, Hollow, and Quincy. When Ichigo obtained his Soul Reaper powers, his zanpakutou, Zangetsu, manifested as a Hollow version of himself.

Ichigo’s Closeness to the Espada
During Ichigo’s battle with Grimmjoww, Tres Espada, Tier Harribel mentioned that Ichigo’s reiatsu was different from other Soul Reapers, stating it felt much closer to an Espada like them.Espada are Hollow that have gained humanoid form and Soul Reaper powers. That is quite similar to Ichigo, as he is a perfect hybrid of Soul Reaper and Hollow. Ichigo has manifested Hollow abilities such as high-speed regeneration, Hierro, and even Sonido. These are all Zangetsu’s Hollow powers being unconsciously used by Ichigo in battle.
The Espada have an equivalent to the Soul Reapers' Bankai,called Resurreccion. The difference is that while Bankai doesn’t change the shape of a Soul Reaper’s clothes, the Resurreccion changes an Espada’s clothes and even physical appearance. From the moment Ichigo used his Bankai for the first time, his clothes changed drastically. In a conversation with Retsu Unohana, Ichigo states that his kimono changes with how much energy he has, showing his appearance is directly linked to his powers, unlike other Soul Reapers. The nature of Ichigo’s Soul Reaper powers has always been distinct from his peers.

What or Who is Full Hollow Ichigo?
Ulquiorra had just functionally killed Ichigo, andOrihime’s all-powerful healingwas not working on him. And then, after hearing her cries, Ichigo rises again, with all white skin, long hair, and a full Hollow mask adorned with big horns. Ichigo fights and completely decimates Ulquiorra, easily surpassing Ulquiorra’s monstrous power. Ichigo, in this form, doesn’t speak, only roars like a beast, and he fights viciously and brutally, completely unlike his usual self, and as soon as the transformation ends, he has no recollection of what happened.
The one who fought and defeated Ulquiorra was not Ichigo, but Zangetsu, taking control of his body and using Resurreccion to bring forth his true power. In this form, Zangetsu closely resembles White, the origin of his power when he was still a Hollow. He has almost the same mask, hair, and roar. The tips of White’s blade arms are identical to Tensa Zangetsu’s blade.

During their last training session, Zangetsu warned Ichigo to not let himself die, as he would take that chance to take control of his body. In this instance, Zangetsu fulfilled that promise. Zangetsu was too much to handle for Ulquiorra, and his beastly fighting style and overwhelming power destroyed the powerful Espada.
The reason why this form was never seen again is that, by the Thousand-Year Blood War, Ichigo finally came to terms with himselfand accepted Zangetsu, reaching harmony within himself.
Bleach
Based on Tite Kubo’s battle shonen manga, Bleach centers around Ichigo, a high school student who is dragged into the world of Soul Reapers. The original anime ended in 2012, but it was revived in 2022.