Highlights

• Vasto Lorde Ichigo's iconic transformation, the result of Zangetsu's takeover, shows overwhelming power against Ulquiorra.
• The origin of Ichigo's powers lies in his unique hybrid nature as a mix of Soul Reaper, Hollow, and Quincy, manifesting itself in his abilities.
• Ichigo's transformation into Full Hollow Ichigo during the intense battle with Ulquiorra shows Zangetsu's true power and control over his body.

WARNING: The following contains spoilers for the Thousand-Year Blood War arc.

During the important Hueco Mundo Arc Bleach, Ichigo Kurosaki battles Cuatro Espada, Ulquiorra Cifer for the safety of Orihime Inoue and the chance to finally escape the nightmare castle. However, after Ichigo's defeat and apparent death, he rises once more, donning a form seen only this once. What fans call "Vasto Lorde Ichigo" remains one of the most iconic transformations from one of the most famous battles in shōnen anime. But the true nature of this form, why and how it came about, continues to be a hotly debated topic among viewers.

With the rebirth of Bleach Thanks to the Thousand-Year Blood War anime, many anime fans who missed the original series finally got a chance to catch up with the new phenomenon. While watching the Arrancar Arc, Ichigo's seemingly inexplicable transformation left new fans, while incredibly excited and surprised, also quite confused, as this monstrous appearance catches viewers off guard.

The origin of Ichigo's powers and Zanpakutou

As revealed during the Everything but the Rain and The Blade is Me mini-arcs, the old man in sunglasses in Ichigo's inner world is not the true spirit of his Zanpakutō, 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, fought a special Hollow created by Sosuke Aizen named White. White was created by fusing the souls of many Soul Reapers and then Hollowfying them, 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 his life. This resulted in Ichigo, a perfect hybrid of a Soul Reaper, Hollow, and Quincy. When Ichigo obtained his Soul Reaper powers, his zanpakutō, Zangetsu, manifested as a Hollow version of himself.

Ichigo's closeness to the Sword

During Ichigo's battle with Grimmjow, Tres Espada, Tier Harribel mentioned that Ichigo's reiatsu was different from other Soul Reapers, stating that it felt much closer to an Espada like them. Espada are Hollows that have gained humanoid form and Soul Reaper powers. This is quite similar to Ichigo, as he is a perfect hybrid of a Soul Reaper and a Hollow. Ichigo has manifested Hollow abilities such as high-speed regeneration, Hierro, and even Sonido. These are all of Zangetsu's Hollow powers being used unconsciously by Ichigo in battle.

The Espada have an equivalent to the Soul Reapers' Bankai, called Resurreccion. The difference is that while Bankai does not change the shape of a Soul Reaper's clothing, Resurreccion changes the clothing and even the physical appearance of an Espada. From the moment Ichigo first used his Bankai, his clothing changed drastically. In conversation with Retsu Unohana, Ichigo states that his kimono changes with the amount of energy he possesses, showing that his appearance is directly tied 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, and Orihime's all-powerful healing wasn't working on him. And then, after hearing his screams, Ichigo rises again, with all-white skin, long hair, and a full Hollow mask adorned with large horns. Ichigo fights and completely decimates Ulquiorra, easily overcoming Ulquiorra's monstrous power. Ichigo, in this form, doesn't speak, only roars like a beast, and fights violently and brutally, completely unlike his usual self, and once the transformation ends, he has no memory of what happened.

The one who fought and defeated Ulquiorra was not Ichigo, but Zangetsu, taking control of his body and using Resurrection to bring out his true power. In this form, Zangetsu greatly resembles White, the source 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 those of Tensa Zangetsu's blade.

During their final training session, Zangetsu warned Ichigo not to let himself die, as he would seize the opportunity to take control of his body. In this instance, Zangetsu made good on that promise. Zangetsu was too much for Ulquiorra, and his bestial fighting style and overwhelming power destroyed the mighty Espada.

The reason this form was never seen again is that, in the Thousand-Year Blood War, Ichigo finally came to terms with himself and accepted Zangetsu, achieving harmony within himself.