The ARX-7 Arbalest is a customized M9 Gernsback designed to house an experimental Lambda Driver. It has a sophisticated AI system which only allows Sergeant Sousuke Sagara to be its pilot. The Arbalest is highly agile, but its top speed cannot be determined due to the volatility of the Lambda Driver. The most notable feature of the Arbalest is the head design with the horizontal mouthpiece that functions to hold an anti-tank dagger.(from Full Metal Panic Wiki)
Battle vs. Gundam Epyon (by FilBox101)Edit
Winner: Gundam Epyon
Zechs has fully mastered the Epyon system, and this system allows him to predict his opponent's moves and full arsenal. The Epyon is also made up of stronger and more durable materials, faster, and once it gets up close, the Arbalest doesn't stand a chance. Arbalest may be driven by a better and more experienced pilot, but the Epyon is just more advanced through and through.