TV-Series
Description
Derflinger is an ancient sentient sword originating from Halkeginia's foundational era over 6,000 years ago. Created by Sasha, the first Gandálfr, using elven magic and spirit-binding techniques, he is a "spirit sword." If his physical form is destroyed, his consciousness transfers to another blade after several weeks.

He typically appears as a weathered but functional broadsword, initially discovered in a Tristain weapons shop priced at 100 gold coins. Despite his unassuming look, he speaks with a distinct male voice, characterized by informal speech and occasional sarcasm. His primary ability absorbs magical energy directed at him, though this process slows and becomes less effective against higher-tier spells like those from square-class mages or mythical entities such as ancient dragons.

Functionally linked to the Gandálfr legacy, Derflinger serves as the designated weapon for successive Gandálfr wielders. He states his partnership with Saito Hiraga is fated, reinforcing his role as both armament and mentor. His extensive lifespan grants broad historical knowledge, enabling him to identify obscure magical phenomena, rare lineages like void mages, and supernatural entities such as rhyme dragons in disguise. However, his memory exhibits gaps due to age, occasionally requiring prompting for specific details.

Throughout his tenure with Saito, Derflinger actively participates in combat, notably during the confrontation with Fouquet's golem where he demonstrates durability and advises strategic weapon use. He later aids against threats including hooded assailants and geopolitical conflicts from Reconquista's uprising. His consciousness temporarily inhabits modern weaponry like a WWII-era Zero fighter plane when necessary.

Beyond martial functions, he frequently comments on Saito and Louise's evolving relationship and occasionally offers romantic advice despite lacking personal experience with human emotions. This emotional spectrum manifests as expressed happiness during camaraderie, distress during Saito's near-death experiences, and sardonic amusement during social interactions.

Critical revelations emerge later: his physical form shatters during a battle against an ancient dragon, though his consciousness survives by merging with Saito's Gandálfr runes. He subsequently reveals his involvement in pivotal historical events, including being the weapon that fatally wounded the void mage founder Brimir during a conflict instigated by Sasha, establishing his direct connection to Halkeginia's mythological foundations.

His final narrative arc confirms his persistence as a non-corporeal entity residing within mechanical systems, specifically within the control panel of a fighter jet, sustaining his partnership with Saito.