Desla is the supreme leader of the Great Gamilas Empire, an interstellar nation facing the slow death of its home planet. He serves as the primary antagonist for the crew of the Space Battleship Yamato, driven by the desperate need to find a new world for his people, which leads him to set his sights on conquering Earth. Initially, his character embodies the archetype of a cold and calculating despot, presenting himself as an elegant but ruthless aristocrat who rules with an iron fist and does not hesitate to eliminate anyone he deems vulgar or incompetent.

Despite this冷酷 (ruthless) exterior, Desla is not a villain motivated by simple personal gain or malice. His actions are consistently portrayed as being for the survival and prosperity of the Gamilas people, making him a complex leader rather than a purely evil figure. He is highly intelligent and strategic, initially dismissive of the Yamato as an insignificant threat but gradually developing a deep respect for its crew as they repeatedly prove their strength and resolve. His personality is marked by a peculiar sense of honor and aristocratic decorum; in one notable instance, he sends the Yamato a congratulatory telegram after they successfully navigate one of his deathtraps, and he posthumously honors a defeated commander and his crew for fighting bravely.

Desla's role in the overarching narrative is transformative. He begins as the absolute ruler of the enemy empire, a distant figure orchestrating the annihilation of Earth from his throne. However, as the series progresses, he is forced to confront the Yamato directly. Following the destruction of his original empire, his role shifts from a conqueror to a wandering survivor obsessed with revenge. This evolves further into that of a reluctant ally and, eventually, a steadfast comrade-in-arms. He becomes one of the only beings in the universe who truly understands the Yamato's spirit, willing to sacrifice his own fleet and even his life to aid them against greater threats like the White Comet Empire and the Dark Nebula Empire. This evolution is so marked that his journey from a cold-blooded leader to a sympathetic figure who values love and sacrifice is considered a defining element of his character.

Key relationships drive much of this development. For Susumu Kodai and Captain Okita, Desla transforms from a hated enemy into a respected rival and, finally, a trusted ally who shares their understanding of duty and honor. On the Gamilas side, his relationship with his subordinates, such as the loyal leader Melia and the pragmatic General Domel, highlights his capacity for leadership and occasional mercy. The character undergoes substantial development across the series installments. In his earliest appearances, he is a static symbol of imperial evil. The sequel Farewell to Space Battleship Yamato: Warriors of Love shows him as a defeated general, fighting with a sense of tragic nobility and choosing a warrior's death over surrender. Ultimately, in series like Yamato 2, he completes a full heel–face turn, realizing his spirit is closer to the humans of Earth than to their mutual alien enemies, and he reconciles with them.

Desla possesses several notable abilities and traits. He is a master strategist, famous for his complex battle tactics, three-dimensional thinking, and the creation of devastating weapons like the Desla Cannon and the Desla Mines. His personal equipment is distinctive, including a high-collared cape that inexplicably billows even in the vacuum of space and a personal starship designated the Desla. He is also shown to be a capable combatant in personal combat, often leading boarding actions and wielding a pistol with deadly accuracy.