Aidan has spiky, silver hair, dark grey eyes and fair skin and attire consists of a green coat over a red shirt and trousers, and blue shoes.
He is referred to as "The Eternal Darkness" by some of the tablets within the castle and by his sister Alexis (who isn't too fond of the name).
His battle machine, the Death Orb MK:II is a purple orb with a well pronounced face and two eyeholes which are the cockpit for Aidan and Ataraxis.
After the defeat of Ataraxis, Serenity marches on to the final battle. She can choose not to avoid conversation with Aidan (which is useful for skipping his long dialogue) and will then fight him.
Aidan can teleport and either fire several energy orbs from the sky or two cris-scrossing emerald fireballs. Once he goes down, he'll get into his battle machine: Death Orb MK:II. The machine will try to crush Serenity and releases shockwaves upon hitting the ground; hitting in the eye is key to victory. Once it goes down the first time, it come back with platforms surrounding it and spikes jutting from the floor. Angel enemies will also appear to fight the player as well. When it's defeated again, it'll return for it's final round. It will move around the arena with several smaller eyeballs surrounding it. Once that's defeated, Serenity will have ended the Castle Master's threat only for an escape sequence to occur.
He later makes his first physical appearance in the Top Floor Throne Room, where he battles against Serenity Horton. Serenity manages to defeat him, though briefly - he and his fiancée Tranquility pilot the Death Orb Mk. II. After another long battle, Serenity emerges victorious.
- Aidan is the final boss, but a true final boss has been confirmed. As the final boss, he only has one actual phase, the last 3 are fought in his Death Orb MK: II.
- Aidan uses the Doctor's A.I whereas the Death Orb MK:II uses the A.I of Ballos (Phase 2), Ballos (Phase 4) and Ballos (Phase 3) respectively.
- Death Orb MK: II's second phase shows both Ataraxis and Aidan piloting it though they aren't visible in the machine's first or final phase.
- Despite being a driving force in both Lunar Shadow mods, he's currently only fought in Lunar Shadow (and not its prequel).
- Both he and Grialdyn use emerald colour projectiles during their battles, furthering Grialdyn's ties to the Castl Master.
- His sprites were reused from Vion Ierra and were in that mod used for a different character. Aside from that, Aidan and the other character are completely different characters.
- He is based off The Eternal Darkness (a member who impersonated Shane and created a mod known as Shane's Cave Story) and Aidan Von Ventus, a member of Vresun. The former has long been speculated to be Shane's alternate account (For example T.E.D's original name, Ashen is an anagram of Shane) though on August 1st 2020 it was confirmed that both he and Shane were sockpuppets. Due to being based off T.E.D, he's also rather foul-mouthed hence why he's one of the few characters in the game to cuss (albeit censored out).
- His family's surname is the name of a one-handed sword (with a curvy patterned blade).
|Characters (Lunar Shadow ZERO)|
|Aidan Flamberge • Aion • Alexis Flamberge • Ariâ • Axlvolt • Ciel Sorcière • Élea • Eron Alexis Armweak • Evan O'Neill • Martel Aar • Selena Daria van der Merwe • Serenity Horton • Shana • Shyn Wau • Ýggdræl • Zsîros|
|Characters (Lunar Shadow)|
|Aidan Flamberge • Alexis Flamberge • Aqua • Azehr • Cheriza du Blaze • Eron Araia Armweak • Evan O'Neill • Grialdyn • Hiranya Mitsuru • Ignis du Blaze • Ilina Horton • Invidia • Irving • Ladislaw Smit • Lunadine Crimstaine • Micren • Noxakaisink • Selena Daria van der Merwe • Serenity Clones • Serenity Horton • Shiki Tashiki • Shinica Horton • Shiori Shauntal • Sycor • Terra • Tia and Mat • Valerie Horton • Valkyrie Horton • Xydia Horton • Xyz|