Leonardo Medici Bundle operates as a chief officer in NeoNeros's Docooga Crime Syndicate, adopting the alias Prince Eharn for North American operations. His full name evokes Leonardo da Vinci and Lorenzo de' Medici, mirroring his cultured nature. Presenting as a dandy aristocrat, he is often seen holding a rose or red wine, maintaining a sophisticated demeanor with ochre hair, green eyes, and a height of 1.85 meters.

Initially an antagonist, Bundle aids Docooga's efforts to seize Beamler energy technology and destabilize the GoShogun team. His trajectory shifts dramatically during the series' climax when he defects from NeoNeros alongside fellow officers Yatta-la Kernagul and Suegni Cuttnal, joining the protagonists to overthrow their former leader. This pivotal turn reveals his capacity for moral complexity beyond initial villainy.

Decades later in *The Time Étranger*, Bundle reunites with former allies at comatose Remy Shimada's hospital bedside. Within her subconscious struggle, he emerges as a philosopher and cultured combatant, utilizing a supersonic jet stored at his Japanese-style estate and commanding a police motorcycle during a high-speed chase. Demonstrating unwavering loyalty throughout Remy's psychological ordeal, Bundle engages in a bar brawl where he plays piano amidst escalating chaos until combat interrupts him. His interactions with Remy hint at longstanding mutual attraction, reinforced by artistic interpretations beyond the screen narrative.

During the film's climactic battle against the metaphysical Beast of Fate, Bundle fights alongside comrades using coordinated tactics, including back-to-back maneuvers with Killy Gagly. His arc culminates in the collective effort to empower Remy's survival resolve through shared spiritual resistance against impending mortality.