Ichigo Kurosaki's true Bankai is called "Tensa Zangetsu." Bankai is the highest level of release for a Zanpakuto, unlocking immense power and abilities for a Soul Reaper in the "Bleach" series.

Tensa Zangetsu represents the true form of Ichigo's Zanpakuto and is characterized by a significant transformation in both appearance and abilities. When Ichigo activates Tensa Zangetsu, his blade undergoes a dramatic change. The sword becomes sleeker and longer, and Ichigo's attire alters, with a black cloak forming around him.

In Tensa Zangetsu Bankai, Ichigo gains enhanced speed, strength, and agility. His cutting power increases significantly, and his spiritual pressure becomes immense. This form also allows Ichigo to perform powerful techniques and attacks, such as Getsuga Tenshō, with amplified destructive force.

It's worth noting that throughout the series, Ichigo's Bankai undergoes further evolution and enhancements as he grows stronger and gains more control over his powers. These evolutions include the appearance of different variations, such as "Mugetsu" and "Bankai: Hollowfied Zangetsu." However, Tensa Zangetsu is considered the true Bankai that represents Ichigo's core powers and abilities.