Mardal, an exile from the planet Lanplate in the Crescent Galaxy, seeks to revive Arst's ancient robotic panzers, forging an army to reclaim his home world. His invasion begins with a brutal assault on House Volder during Prince Jordy Volder's birth celebration, slaughtering the king and capturing Queen Felia. He preserves her conscious yet paralyzed form in crystalline stasis as a trophy.

Twelve years into his conquest, Mardal rules Arst as a merciless overlord, exploiting its resources to fuel galactic domination. His strategy masks sadism, treating Arst as a mere stepping stone to ignite wider conflict. This sparks rebellion from subordinate General Zaba, who resents Mardal's disregard for Arst beyond its utility.

Physically, Mardal embodies antagonism with a bald head and beard. He commands elite warriors like Hy Shaltat through transactional loyalty, enforcing authority without camaraderie. His warmongering stems from Lanplate's culture of extreme apathy and emotional stagnation, an attempt to shock his indifferent home world into awakening through war.

Mardal's ambition collapses when the Advanced Civilizations Union annihilates Lanplate with the Eraser weapon, preempting his galactic war. Confronted by his home world's imminent destruction and the futility of his campaign, he surrenders, joining his people in their final moments. The OVA *Crest of Iron* maintains his core role and motivations, introducing variant mecha designs like the Jashinhei without altering his backstory or character.