The EX-178 served under the rule of the Great Garmillas Empire as a battlecruiser. But upon a failure of the warp core during faster-than-light process en route caused the ship to drop out into the fourth dimension, where it was hopelessly adrift. When the Yamato enter the same trouble and the two vessels meet up, Lang proposed to have a momentarily truce between them, for the favor to use the Wave Motion Gun to create a dimensional rift and in return, the EX-178 will pull them out. To ensure that the Garmillas ship would not abandon Yamato, a member of the EX-178 crew, Lower Storm Leader Melda Dietz, was sent to Yamato. During the towing process, conflict broke out among a the crew, but it was soon settled. Upon exiting the dimension, as stated in the truce, the vessels are now respectable enemies. But the assault was eternally halted by in intervention by Goer, who ignores their presence and open fire at the Yamato. The battlecruiser was caught under friendly fire and exploded. The Yamato saluted its crew as they passed its wreckage and Dietz became a prisoner of war because of its destruction ("Graveyard of the Universe").