Spitfire, the Inferno Mini-BOT can be crafted using fragments dropped in Inferno 1(Entrance) and 2(Ramparts). 3 fragments of the same version and a crafting coupon is needed to create a Spitfire. Spitfire comes in 5 versions each one giving a small HP boost plus more:

VIT = Further increases the HP boost
ADAP = Gives an increase to Trans Gauge, Trans Bot Attack, and Ranged Attack
ROID = Increase your Health further by equipping more Trans Speed, intended to give Rams a way to be more tanky
ASSN = Increase your basic damage further by equipping more Speed, intended to give Surges a new way to fight more like an assassin
ATK = Increase your your transformed damage further by equipping more TransAttack, intended to give Patches a more overall offensive approach in and out of transformation