- "My name is Eonia! I will show my power before Transbaal's history and carve my name into eternity!"
- — Eonia Transbaal —
Eonia, as described by multiple occasions, is a young and charismatic man blessed with an attractive visage and figure. His long, orange hair reaches down to his feet and he is dressed in a royal military outfit with purple, red, and white highlights. Accompanying his outfit is a black sash embroidered with a gold sigil.
Prior to the events of Galaxy Angel, Eonia was exiled to the outer frontiers in due to his extremist views on utilizing Lost Technology to expand the empire. He was accompanied by his loyal followers until they discovered the Black Moon and planned for their return home. At the start of the game, Eonia's enormous fleet breaks through his homeworld's defenses and he razes the capital to the ground, killing his entire family save for his cousin, Shiva, who was on the White Moon.
Eonia's fleets, after confirming Shiva's transfer to the Elsior, would begin to pursue in hopes of gaining access to the White Moon. He himself would not be encountered until the later half of the games where his hologram would appear on Fargo before its eventual destruction. His subordinate Sherry is sent ahead of him to route the Elsior's race to the White Moon while his fleet prepared itself for the inevitable battle near Transbaal. After Sherry's sacrifice and Noa's upgraded ships not being able to best the Angel Wing, Eonia meets his death by the unleashed Chrono Break Cannon.
At the end of all the Angel's routes, with the exception of Milfeulle's, the Elsior is assigned to search for the remnants of Eonia's forces out in the outer reaches of the empire as their public guise. The true purpose of this expedition was to make sure no other powerful Lost Technology would fall into the wrong hands. Shiva muses at how Tact will be doing exactly what Eonia was doing but Tact responds that while Eonia was looking to the past, they are looking to the future.
It is interesting to note that Eonia's intentions to increase Transbaal's strength through expansion would have been correct as the threat that would succeed him would be the Val-Fasq as both Noa and Shatoyarn would eventually come to terms with working together which the Black Moon would have done anyway.
Eonia is portrayed as highly intelligent and charismatic, yet ruthless individual. He held the grudge of his exile close to his heart and continued to strive for Transbaal's future under his ideal after his forceful coup. Nonetheless, he also displays affection for those around him such as Sherry Bristol and Noah. Sherry in particular he felt certain sorrow for, as her sacrifice to buy him time lead him to question her actions as he wished for her to remain with him. He also respected Tact's leadership for surviving so far in interfering with his operations. It would be Tact's rather lack of notoriety that would ultimately lead to Eonia's defeat as the young and unknown commander's skill went under the radar while Eonia eliminated most of the empire's military heads.
- There a joke in the manga and game that Ranpha would not mind Eonia being her boyfriend if he was not evil. In the Manga there was a side comic page that had Eonia kidnapping Ranpha for her to become his wife. This is mention again in GAII manga 4kome if Ranpha was instead the gatekeeper, she tells Verel that she already been kidnapped once before by Eonia.
- In the manga, Eonia found out that Prince Shiva was the result of Emperor Gerald and Shatoyan's affair, and was exiled to silence him.