|A century ago, a mere human slayed the Devil of All Earth and became the renowned Marleyan hero who saved the world--Helos.|
|— Willy Tybur recounts Helos' legend|
Helos (ヘーロス Hērosu?) was a key figure in Marleyan legend and military history, and a participant of the Great Titan War, renowned for slaying the Devil of All Earth. The story of Helos was fabricated by the Tybur family and Karl Fritz to worsen the Eldian civil war, and it is unknown whether or not Helos ever truly existed.
According to legend, Helos was a brave and heroic man, willing to face off against the Devil of All Earth despite the overwhelming odds. He was also clever and cunning, able to fuel the in-fighting among the Eldians and bring about the fall of their empire.
When he inherited the Founding Titan, Karl Fritz decided to conspire with the Tybur family to send Eldia on a path towards destruction as retribution for the atrocities the empire committed throughout humanity's history. As part of this effort, the Fritz and the Tyburs instigated the continuing Eldian civil conflicts by fabricating a Marleyan hero known as Helos. Legends would later tell that during the Great Titan War, Helos slew the Devil of All Earth and conspired with the Tybur family to overthrow the Eldian Empire. Through their combined efforts, Marley was able to conquer Eldia's mainland territory and acquire seven of the Nine Titans, and force Karl Fritz to relocate the capital of his empire to Paradis Island. Throughout this conflict, Helos acted as a figure of leadership on the Marleyan side of the war and ensured the nation's victory.
In the aftermath of the Marley Mid-East War, the Tybur family visits Liberio shortly before a festival in which Willy Tybur, head of the household, is to address an international press conference. During this visit, Willy admires the statue of Helos slaying the Devil and later expresses his fondness of the hero to Commander Magath. However, Magath is less impressed with the display, considering it to be as hollow as Marley's reputation.
One month later, the story of Helos is recounted to the world leaders and ambassadors in Liberio during a play performed by Willy Tybur and his actors. Shortly afterward during the play, Willy reveals to his audience that the story of Helos was all fabricated to cover the truths of the Great Titan War and the agreement between the Tybur family and Karl Fritz a century ago.
- The romanized katakana for Helos's name is visually similar to the ancient Greek word ἥρως (hḗrōs), which the English word "hero" is derived from. However, the pronunciation is not the same.