Jackknife Dragon, alias Findar the 100th, is a green-scaled dragon and unwavering companion to Tasuku Ryuenji. A former Buddy Police operative, he forges a familial bond with Tasuku, vigilantly safeguarding his partner’s life and refusing to diminish his imposing stature in everyday situations, asserting his role as a constant protector. His combat prowess ascends through rigorous training under Dynamis—disguised as Tasuku’s past alter ego, Purgatory Knight—culminating in a metamorphosis into the Neodragon Star Guardian, Jackknife, adorned with sleek futuristic armor and a neon-blue blade. Subsequent evolutions reshape him into Radiant Guardian, Jackknife "Aster," marked by golden armor and azure hues, then into Star Dragoner, Jackknife, a fusion of his prior forms. A fracture in their bond emerges when Tasuku forcibly converts him into Goldritter, a soulless weapon, spurring Jackknife to ally with Team Balle Du Solle and mend their trust. In a climactic battle, he overpowers Demios Sword Dragon and liberates Tasuku from corruption’s grip, later temporarily embracing a diminutive SD form—a concession to his pride—to console his guilt-ridden partner. Though typically composed and duty-driven, Jackknife reveals dry humor, notably mocking a foe’s ill-placed core gadget. He extends clemency to former adversaries like Kiri and mentors younger entities such as Bal Dragon with paternal patience. Reluctance toward his SD form fades as Tasuku’s emotional needs take precedence. Ultimately, he harnesses the essence of the Star Dragon World, transcending into a paragon of guardianship. Across chronicles, his loyalty remains ironclad, blending strategic ingenuity, combat versatility, and empathetic resolve to uphold justice alongside those he cherishes.