Model F

Fighting Fefnir - 'The Flame Mega Man'

Model F was stolen in the first ZX game by Serpent and split into two halves to create Fistleo the Predatoroid and Flammole the Moleroid. Once attained by Vent/Aile, he/she gains access to Model F's abilities by Double Megamerging it with Model X to create Model FX. This Model makes use of the Knuckle Busters (Nichou) based on Fefnir's arm cannons Sodom and Gammorah, has fire element attacks, and is good in both long-ranged and melee combat.

The Knuckle Busters can fire upwards as well as sideways. Attacks and abilities specific to this Model include the Megaton Crush, which only needs a half-charge, a large fireball attack, and Ground Break similar to the charged version of the Fire Wave used by X in the first X game. Ground Break is needed to get some blocks that are in the way to certain areas. Model F's Buster Edit skill allows an individual path to be set for both Knuckle Busters' shots. When not in used, the Nichou are stored in a special socket attached to the jacket with the FX version bearing a closer resemblance to how Fefnir had his stored Sodom and Gammorah.

Model FX resembles Fefnir somewhat vaguely; the dragon motif of his original armour is absent, with the helmet ornaments mounted at the back, no longer resembling fangs. His password is Flamma Wies, a corruption of 'Flamma Vis', which means 'Power of Flame' in Latin. Unlike most of the Biometals, Model F/FX does not feature jewels on the gauntlets and appear more blocky than round.

In Mega Man ZX Advent, Biometal Model F is used against its will by a new Chosen One by the name of Atlas. Her manifestation of Model F bears closer resemblance to Fefnir, with the helmet ornaments mounted on the front instead of the back. In Ashe's story, Atlas can use this Biometal to lay bombs.