B't Max is a massive mechanical entity modeled after the Black Tortoise (Genbu) of Chinese and Japanese mythology. She primarily dwells underground while her donor, Hokuto, conducts experiments within her internal laboratory. Max's outer armor possesses exceptional durability, impervious to attacks like underground missiles.

Exhibiting a serious, perceptive nature and emotional depth, Max maintains unwavering loyalty to Hokuto while also willingly interacting with others. Her abilities include generating a Protective Shield, an energy layer that repels surrounding enemies.

Throughout the narrative, Max functions as Hokuto's primary transport and operational base. She facilitates the revival and power upgrade of the heavily damaged B't X within her laboratory under Hokuto's direction. Revelations about Hokuto's past experiences and motivations for joining the Machine Empire deepen Max's connection to him, as their shared history informs their operational dynamic.

During the events of Neo, Max participates in the journey to the Machine Empire's central tower. Her capabilities and laboratory facilities prove crucial to the protagonists' objectives. Max remains engaged throughout the culminating confrontations, contributing her defensive strengths against the Machine Empire's ultimate threats.