"General, haven't you wondered why I do what I do, despite being easily able to retire? I could live out the rest of the world's lifespan completely comfortably. I can crush anyone under my metaphorical boot, but I don't. I do what I do, general, because I am the only man who can do it. There are those who are 'strong,' and those who are 'weak,' but strength only belongs to who is more ambitious. Those who are strong are those who create the justice that the world follows. I must maintain my strength, and keep justice in this world. It is through I, uncorrupted as I keep myself, that we will maintain order. Peace between the different species of Euclid can only be kept by my hand. Come, General, take a seat." —Gabriel Alchemilia, Exit Music
Gabriel Alva Didier Arsene, later Gabriel Alchemilia, is an antagonist in The Demon's Light. He is a century old, if not much older, and hails from the continent of Nuyö. He is the founder and one of the chairmen of Alchemilia Corporation.
Gabriel appears as a man in his early-to-mid thirties, with minimal blemishes or wrinkles on his pale skin. He is extremely gaunt, though not to a disturbing degree, giving him an aura of unease. His lips hold a faint green tint, the only notable colouration on his white skin. Gabriel bears short, straight hair in a bright colour only comparable to white. Occasionally, he wears glasses over sharp green eyes, and under his right eye he bears a scar.
When in meetings with other powerful figures in the company, he dresses in business suits without much notable about them apart from some strange colour choices. Within his jacket is a small pistol, undetectable to most untrained eyes. Over his suit, he normally wears a large, dark overcoat atop his shoulders, with the sleeves draped behind him.
Ceremonially, however, Gabriel wears a double buttoned jacket and turtleneck sweater underneath that leaves no room for a tie or other accessory. He keeps the coat over his shoulders, and wears pants tucked into elegantly designed uniform boots. His attire is sometimes gilded at the edges, and usually comes in shades of blue, green, or black. He dresses like this when addressing members of The Halberd. He wears a gas mask when necessary, to protect his eyes from stray bullets or debris during combat as well as keeping dangerous substances from his lungs.
On his own time, Gabriel dresses in dark grey slacks, kept up with both suspenders and a belt due to his lanky figure. He also wears a faded green turtleneck, tucked into his pants, and beyond that an unzipped jacket with broad shoulders to give the illusion of a more intimidating physique.
Gabriel is a self-described 'Immortalist,' to him meaning a human who has risen above their own mortality to live forever. The means to achieve this do not matter, according to Gabriel, and any human who is impervious to both disease and aging could be considered under the title.
Though it's unknown how Gabriel achieved this state, his life beforehand is well documented. He was born in Thales to two parents, immigrants from Nuyö named Didier and Helena Arsene, in a well-off family of doctors and other intellectual professions known as the Arsene family. He followed in their footsteps along with his three siblings, only one of which was older than him. Luther Arsene, Bea Arsene, and Oedipus Arsene, with Gabriel being younger than only Luther. While they were all geniuses in their own right, Luther was a prodigy beyond any of the others. While Gabriel put his work as a surgeon second, preferring to spend time with an entourage of girls he didn't ever remember the names of, Luther worked on making advances towards curing a number of prion-related diseases. While Gabriel spent his time looking in the mirror and carefully managing every strand of hair, Luther would return to school in order to make progress in the fields of robotics. Gabriel was never envious, as he knew deep-down that he was second to his brother and it didn't bother him at all. He joined Luther in his interest in robotics, and together the prodigies developed a prototype of a humanoid android capable of surpassing a human in combat prowess. Luther had Gabriel, the mastermind of the design, present it to the local government and they found themselves with a government funded project and their own startup company, 'Alchemists Co.'
Through their collective genius, they made incredible strides culminating in a project that was shrouded in secrecy, later known as the Alchemilia Wormhole Project. During the formative years of this project, Luther departed and eventually vanished without a trace. Gabriel, alone in charge of the company, renamed himself to 'Alchemilia' and became a celebrity in the intellectual community. Due to Kaz' interference in the natural order of the universe and the very concept of godhood, the world was in danger. This resulted in the local government swiftly forcing Gabriel to focus the Wormhole Project on bringing the legendary rivals of Kaz' demons, known as the angels, from Eden.
Beyond this, the great war happened and Gabriel found himself leaving the business to a group of chairmen while he focused entirely on the science. He founded the Halberd, became an Immortalist, and slowly amassed power. At some point, eight years prior to the series, he had a daughter named Galena.
- Gabriel Alchemilia is the illegitimate father of Atticus Anoethite
- Gabriel Alchemilia's pose in the image as well as his hairstyle are references to Yoshikage Kira from JoJo's Bizarre Adventure.