Arrancar possess zanpakutō and can perform a technique similar to a Shinigami's release called Resurrección|帰刃（レスレクシオン)|resurekushion|Spanish for "Resurrection", Japanese for "Returning Blade". Unlike a Shinigami's zanpakutō however, an Arrancar's zanpakutō is simply the Arrancar's Hollow power sealed into the shape of a weapon. By releasing their zanpakutō in the same manner as a Shinigami, an Arrancar can release his or her Hollow powers. Most known Resurrección give the Arrancar user an animal-like appearance. While most unreleased Shinigami zanpakutō take the form of a katana or wakizashi, there is a significantly broader range for Arrancar (such as a sai, axe, or a more fictionalized weapon like Nnoitra's zanpakutō).
Because their powers are sealed in their zanpakutō, an Arrancar's release will usually transform their body into a Hollow-like form, allowing them to use their abilities freely. This form usually reflects what the Arrancar looked like as a Hollow, although to highly varying degrees. A Resurrección restores an Arrancar to its "true" form, resulting in significantly various increases in speed, strength, stamina, durability and spiritual power, as well as allowing access to both more powerful variations of previous techniques and completely new abilities. Arrancar normally only return to their human form when they reseal their Hollow powers; doing so without resealing, though possible, is a permanent change comparable to amputating a limb. There are two reasons Arrancar go through such trouble to seal their power: it allows them to maintain human form and to conserve their power in times of inactivity.