Bardiche is an Intelligent Device created for Fate Testarossa by Rynith, the Testarossa family's former cat familiar. Possessing a male gender identity and an old-fashioned manner, Bardiche addresses Fate as "sir." Its name originates from a historical polearm used in medieval and renaissance Europe, particularly in Eastern Europe and Russia. Initially a standard Intelligent Device, it appears as a golden triangular gem on a pedestal in Standby Form. Its primary forms include Device Form (a bearded axe for melee combat and ranged spells like Photon Lancer), Scythe Form (featuring a mana blade for Arc Saber), and Sealing Form (a spear-like configuration with energy fins for sealing spells).

Severely damaged battling Signum's Laevatein during the A's storyline, Bardiche is upgraded by Mariel Atenza into Bardiche Assault. This upgrade incorporates a six-cylinder revolver-style Belkan Cartridge System below the axe head and introduces Haken Form (an enhanced scythe with additional fin blades) and Zanber Form (a claymore-like energy blade for high-output attacks like Plasma Zanber). By StrikerS, Bardiche Assault develops Riot Blade (a compressed saber), Riot Zanber Stinger (dual blades connected by a mana string), and Riot Zanber Calamity (combined into a larger blade). During Force, it undergoes another upgrade to an experimental "5th Generation Device," capable of converting mana into physical energy to counter anti-magic effects, including enhanced versions Riot Blade II and Riot Zanber II.

Within the movie continuity, Bardiche's design diverges early. Its Device Form is redesigned as Axe Form with a rounded blade and elongated spikes, while Sealing Form becomes Glaive Form with three mana blades. After the upgrade in Reflection, Bardiche Assault is further modified into Bardiche Hornet due to urgent circumstances. Hornet features only two active forms: Straight Saber Form (an enhanced energy sword replacing Zanber Form) and Javelin Form (a polearm optimized for bombardment). Its Standby Form also changes to resemble the hilt of Straight Saber Form, carried in a briefcase.

Titled the "Battleaxe of Flash" by Rynith upon creation, Bardiche remains Fate Testarossa's primary combat device across all continuities.