Lady Armaroid began life as Princess Emeralda, a human rebel leader opposing the tyrannical King Giros on her home planet. Suffering critical injuries during the conflict, she underwent transformation into an Armaroid. This mechanical form utilized advanced "live metal" technology from an ancient Martian civilization, preserving her consciousness while granting superhuman capabilities and erasing all physical traces of her humanity.

Cobra intervened in her rescue, forging an alliance with her rebellion that deepened into a profound bond of unspoken trust and mutual reliance. As an Armaroid, she possesses enhanced strength, durability, and technical skill, primarily piloting the spaceship Tortuga and providing tactical support. She avoids direct combat and conventional weapons, relying instead on analytical and operational expertise.

During Cobra's period living as "Johnson" with altered appearance and erased memories, she disguised herself as his robotic servant, Ben, for covert protection. When Cobra's true identity reemerged, she abandoned the disguise to aid him against threats, reigniting their adventures. Her past as Emeralda resurfaced when her mechanical body destabilized, compelling Cobra to delve into their shared history for a solution, highlighting her dependence on him and their enduring connection.

Throughout their exploits against adversaries like the Pirate Guild, her role transcends technical functions. She serves as Cobra's emotional anchor and moral compass, tempering his impulsiveness with her composed presence. Their relationship, built on loyalty and shared history, remains fundamental to their endeavors.