Fighting Fefnir

Fighting Fefnir (「闘将」ファーブニル) is a video game character in the Mega Man Zero video game series. He is voiced by Kazuya Nakai. Fefnir is the leader of the Jin'en Gundan ("Army of Ash Flames") with the title of Tōshō ("Fighter General" or "Fighting General") for Neo Arcadia. Fefnir's schematics were based on that of X's capabilities of ground combat. He is one of the Four Guardians (四天王) designed to protect Master X. He wields two arm cannons, named Sodom and Gommorah. He was fiercely faithful to Master X and oversaw a pupil, Anubis Necromancess III.

History
After Anubis was defeated by Zero in the first Mega Man Zero, Fefnir launched an assault on the Resistance Base, going through the treacherous desert in which his pupil was destroyed. This assault was thwarted by Zero and he himself was defeated. He was defeated again by Zero in a Neo Arcadia Core, but rose again to defend the Inner Sanctum of "Area X" where Copy X resided. He was told, along with other Guardians, to step down. Copy X was destroyed later.

When Elpizo launched a full frontal assault against Neo Arcadia in Mega Man Zero 2, Fefnir battled with the remaining Guardians and killed the invading force. They would have killed Elpizo too, had Zero not rescued him.

Later when Elpizo tried to infiltrate the Sanctum of Yggdrasil where Original X lay dormant, Fefnir tried to stop him in his second form that resembles a tank. However, he became infected, possibly with the Baby Elves, though the English Translation of Mega Man Zero 2 makes it sound as if he was infected by some kind of virus. (Leviathan states that "It looks like Fefnir's disease infected me".) It made him incapable of thinking of anything other than fighting Zero, and helped him transform into a terrifying battle form, that was eventually defeated.

Though defeated, Fefnir was not destroyed, and later took part in mission to investigate the wreckage of a crashed spaceship that contained the exiled Reploid, Omega at the beginning of Mega Man Zero 3. He was heavily damaged in the battle and did not reappear again until the final battle with Omega, only being mentioned, along with Leviathan, once in the game, in which Harpuia remarks to X that "Fefnir and Leviathan are still undergoing repairs".

According to the Rock Man Zero Official Complete Works artbook, Fefnir, along with Harpuia and Leviathan, died at the end of Mega Man Zero 3 under Omega's explosion.

Personality
Fefnir loves battle, and even gets disappointed upon being told to step back. He is likely modeled after X and is unquestioningly loyal to him. He is proud of his position in Neo Arcadia and sees it as a true peaceful utopia, despite his violent tendencies. Fefnir rivals Zero because he envies the fact of Zero's past with X. He knows well of Zero's power but hates him only because of the side he fights for.

Other Appearances
Fefnir also appears in Mega Man ZX as Biometal F. Vent or Aile can use Biometal F after combining it with Biometal X to become Model FX. The other guardians also appear as Biometals as well. The personality of Model F is notably similar to Fefnir's personality, even more so than with the other Biometals.

Fefnir also appears in the Manga adaption of the series. He is no longer a copy of X but a new type of Reploid altogether. He was the first to fight Zero and was defeated. When Zero was brought before Cial (Ciel's evil twin), he rejected the thought, stating that he would be watching Zero. Fefnir's (along with Phantom and Leviathan's) suspicions were correct when Zero took Cial hostage. After they got Cial out of Zero's reach Fefnir and the other Generals merged to form "the ultimate Reploid" (Copy X) and was destroyed by Zero.