Garillion is an ancient Aurelus Bakugan with a shaolin-inspired, Kelion-like armored bipedal design. His personality embodies a strong sense of honor and dignity, leading him to initially dismiss Bakugan from other factions as juvenile and avoid their conflicts. Centuries ago, he journeyed to prehistoric Earth alongside Bakugan representing the five factions. When a meteorite threatened the planet, Garillion overcame his reluctance to intervene, united the factions, and called forth the Infinity Armor to fuse into Garillion Infinity. This fusion allowed him to destroy the meteor, though the resulting environmental fallout forced him and other Bakugan into prolonged hibernation.

Awakening after the merger of Vestroia and Earth, Garillion retreated to the Maze. There, he observed and studied the bonds forming between Bakugan and human children. His re-emergence occurred when the alien Haavik deployed the artificial five-headed Bakugan Sabrus against the Awesome Brawlers. Garillion confronted and defeated Sabrus, demonstrating his protective power. Later, recognizing the need for sustained defense, he voluntarily transferred the power of the Infinity Armor to Dragonoid X Aurelus, trusting them to confront Haavik and Sabrus. After this transfer, he returned to the Maze.

Garillion possesses specific ability cards: "Ancient Inferno" in his base form and "Hidden Infinity Attack" and "Infinite Inferno" as Garillion Infinity. His physical design combines elements from existing Bakugan models, specifically Kelion's head and Apollyon's body, and lacks weaponry. Garillion does not appear in the physical Bakugan game, as no Aurelus variant exists for his component models.